[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] jaysoblitzed:
How to Revert to Old Firmware & Root Newest Release -

Hello and welcome to XDA.

I understand your concern to root your device especially with it being on the latest firmware, but I will do my best in order to explain every step to you in the utmost detail. I am currently on I747UCLH9 with a Custom ROM. Meaning I kept the Modem & Bootloader and kicked the Kernel and Firmware. Before I begin, I would like to ask you to thank to all the Developers / Posters who made & put this content together as this would not be possible without them. I will link all of their original posts at the end of this. Be sure to give credit to every one of them and please make sure to give thanks to them. I take absolutely NO CREDIT for any of these links/steps whatsoever. I simply researched and compiled them in order to help you. With that being said, let us begin.

Before anything you must remember this. After you are finished downloading whatever items you need, you MUST (and I cannot stress this enough) FACTORY RESET YOUR DEVICE. Reason being is because a lot of other people have tried this same process of downgrading without wiping and ended up getting startup boot errors. Be sure to NOT sign into your Google account. This is just a warning, follow the steps below to know when you should begin this process.

All files you download should be saved on your desktop. Personally I prefer to make a separate folder for these kind of delicate things. Keeps it organized so you don't forget where you are.

Make sure your phone IS NOT plugged in to your computer as of right now & you have NO external SD card.

Now;

Let's begin.

Before you start be sure you have the Samsung USB drivers installed. Which you can get from Samsung's website or here.

Samsung USB Drivers

Also be sure that you have WinRAR installed as well which you can get right here.

WinRAR

To be on the VERY SAFE side you must download ADB (Android SDK). What you must do is when it asks you for where you would like to install it, you MUST ONLY CLICK "Local Disk C:" . AND THATS IT. The best thing is to keep it here so when you have to execute a command line, it will be very simple. You will have a folder called "android" here. THAT IS YOUR ADB FOLDER. You will understand what I mean shortly. *Note* this is for CWM-T (ClockworkMod Touch).

Android SDK

1. Download the stock rooted LG1 Firmware. I747UCLG1 Stock + Root Only.

2. Right-Click the LG1 Firmware you just downloaded and extract it. It is currently root69.stock_ATT_I747UCALG1.7z ; the extraction process will turn it into the correct .tar file (Flashable file type with Odin)

3. Now that you have the Stock ROM, you need..well ODIN! Here's the link. Odin 3.07.

4. Since it is in .zip format you need to extract this as well. You will end up with 4 files. Right-Click on the Odin3 v3.07.exe and run it as administrator. Now you are at the Odin screen with nothing there -_-".

5. Factory reset your phone. Just let it boot up but DO NOT sign into your Google account, just click through skip everything head straight to your Settings, then Developer Options & make sure USB Debugging is enabled/checked. Back out of your settings completely and you are at the home screen.

6. Now, just hit the power button and turn your device off. After it is completely turned off hold the Volume Down + Home button. While holding these 2. Press and hold the Power button. You should now be holding all three buttons at the same time waiting for a green lettered screen to come on (Download Mode). Use the phone keys to select the option to continue. Your phone will now say Downloading, do not turn off device. (Or along those lines).

7. After selecting the option that sends your phone to the screen with the text "Downloading, Do not turn off device." You should be holding your phone in hand with USB plugged into your computer but your device is not connected. Odin is open on your computer screen with nothing still. From here just plug your phone in and you will see a pop-up in the first box of many under the Odin logo which says "COM: #".(#: Being a select number of your device. This is of no importance, as long as you see this pop up.) Once you see this your phone will be ready to be flashed back. Just click the PDA button and browse to the root69.stock_ATT_I747UCALG1.tar file. (Be sure you click the .tar and not the .zip.)

8. Check to make sure no other boxes should be checked except for Auto-Reboot.

9. Press Start and wait for the process to finish.

10. Everything should go through fine and your phone will start back up and you will be on LG1. You are now on stock firmware BUT rooted. Unplug your phone, Skip past everything once again and make sure USB Debugging is enabled. Keep your phone unplugged & don't forget to close ODIN.

Now before you do anything. You need a Custom Recovery AKA CWM. Well in this case we will be installing the latest touch version.

11. Download the latest ClockworkMod Touch from here. This link is saved in a way specifically from their website. You can either go to www.clockworkmod.com and browse the ROM Manager tab for the 6.0.1.4 Recovery. OR you can just right click the link provided right here and press "Save As..." this file will come up and asked to be saved as recovery-clockwork-touch-6.0.1.4-d2att.img. RENAME IT AS "recovery.img" without the quotes & save it.

ClockworkMod Touch 6.0.1.4

12. Now that you have this file. Plug in your phone to your computer and in the root folder of your phone storage and copy the recovery.img file to it; which is the first folder that pops up when you press open when you plug your phone in. (Remember no SD CARDS!)

13. Now, click the Start button on your taskbar and in the search bar type cmd. Now you will see cmd.exe; press enter and you will see the Command Prompt open. If you saved the Android SDK the way I told you to, you can copy and paste the line below. If you saved it somewhere else you can change the folder simply by browsing to the android folder. Make sure you click on the "platform-tools" folder. NOT the "platform" folder. Also whichever directory it is you must add a "\" at the end so it will find the location correctly.

cd C:\android\platform-tools\

14. Now you are in the directory time to run ADB Shell and flash that recovery! Copy and paste or type the following; I recommend you copy and paste the last line as it gets tricky. After the SU command your phone will be detected.

First you type	adb shell

following that	su

and finally	dd if=/sdcard/recovery.img of=/dev/block/mmcblk0p18

As you can see in the last command it is named recovery.img there are no special characters or numbers or symbols to mess with the flashing. After you run this command you will an output similar to the following.

14004+0 records in

14004+0 records out

7170048 bytes transferred in 1.430 secs (5014019 bytes/sec)

Finish up this step with the following command

reboot recovery

15. Your device will now restart and head straight into recovery. Congrats you now have LG1 Stock + Root with CWM-T. Unplug the USB and press "Reboot System".

TO UPGRADE BACK TO LH9 WITH ROOT AND CWM-T

Before I begin.

You must remember that this step REQUIRES you download 4 files to go on the root of your phone memory. Your phone should now be on the home screen. Plug it in and open your phone memory. With that being said you need the following files. The Rom, Modem, Bootloader, and Kernel. You will be flashing them in this following order as well.

16. Download the following pieces and save them to the root of your phone's memory. Be sure to remember which file has what name so when you enter the recovery you aren't lost as to which to flash first.

I747UCLH9 ROM	Download

I747UCLH9 Modem	Download

I747UCLH9 Bootloader	Download

I747UCLH9 Kernel	Download

17. After everything has finished transferring, remove the phone from the computer and turn your phone. Remember how you got into download mode? Well instead of holding Volume Down + Home, you hold Volume Up + Home. While holding these two press and hold your power button until you see it says Samsung Galaxy S III. If you look at the top left hand of the screen while it's JUST turning on. You will see some blue text flash. When you see that you know your entering the recovery and can release the buttons.

18. You are back at the recovery. You must now do the following. Touch the options as I list them. Follow these steps precisely.

- Wipe Data/Factory Reset

- Yes -- Delete all user data

- Wipe Cache

- Yes - Wipe Cache

- Advanced

- Wipe Dalvik Cache

+++++Go Back+++++

- Install Zip from SD Card

- Choose zip from SD Card

Now choose them in the following order, ROM, Modem, Bootloader, and finally Kernel.

WAIIIITTTTTTTT! After you are finished flashing the Kernel you MUST do the following. Click options as I state them.

- Wipe Cache

- Yes - Wipe Cache

- Advanced

- Wipe Dalvik Cache

- Advanced

- Fix Permissions

+++++Go Back+++++

Reboot System

19. Wait for your phone to reboot and NOW you can sign into your Google account. Go past everything go into your App drawer first and check for Superuser/SuperSU once you see that, go into your settings and check your ROM, Modem, Bootloader, Kernel. Yes. They are bone stock with root. Congrats you achieved maximum upgrade with root.

Now I would like to give my shout-outs; Thanks; and share the following posts that helped me compile this. I couldn't have done it without you guys.

neverends - Samsung Drivers & Odin provided. Steps to flash with Odin as well.http://xdaforums.com/showthread.php?t=1722686

mrRobinson - I747UCLG1 Stock root injected file. Location of Odin, and commands to execute ADB shell to flash recovery.

http://xdaforums.com/showthread.php?t=1739426

drothenberger - Provided CWM Flashable version of I747UCLH9. Blessing, really. Stock root with latest FULL update without having to revert back to LG1 stock.

http://xdaforums.com/showthread.php?t=1896773

ALSO

Thanks to you all above; the CWM Team, CM10/AOKP Team, Moderators & Posters alike. None of this would have been possible without you. Keep up the good work. Bless -