[One (M8) Q&A, Help & Troubleshooting] @SidDev:
There are a few basics you need to get out of the way

before you can start this process:

This method will only work for a device that already

has an unlocked bootloader with a custom recovery, so

be sure that you have that before going forward.

Uninstall HTC Sync. The program is great way to get

the HTC One M8 drivers installed, which you will need

for this process, but it will interfere with the tool we

will be using to S-Off your M8.

Enable USB debugging .

Turn off all security settings from Settings -> Security .

Disable Fast boot mode from Settings -> Power/Battery

Manager .

You'll also want to make sure that you are using a USB

2.0 (not USB 3.0) port for this for compatibility

reasons.

Backing up your data is also necessary, just in case

anything goes wrong.

This process works best with a Sense-based ROM with

an insecure kernel, and you can flash InsertCoin in

order to have both of those bases covered.

This section (Steps 1 through 6) will show you how to

to get InsertCoin ready on your HTC One, but if you're

already running a kernel with an insecure kernel, you

can skip this section and proceed directly to the

Preparing Your Device & Downloading Firewater

section below.

We will be flashing the InsertCoin ROM so that we

have a Sense framework and kernel that fits all the

needs of the S-Off tool we are going to use. The

InsertCoin ROM can be downloaded directly from the

InsertCoin Team's website onto your device.

With the ROM downloaded, place your device into

Recovery mode by holding the Power and Volume Down

buttons at the same time, which will take you to the

following Bootloader screen:

Once in Bootloader mode, use the Volume Down key to

highlight Recovery and hit the Power button to boot

into TWRP.

Before going any further, you should make sure to have

a backup of your existing setup since we'll be

performing a full data wipe in the next step.

You can do this directly from TWRP using the Backup

option. After going through the S-Off process, you can

restore this backup to get all your apps, messages, and

settings back as they were before.

From the main TWRP menu, select Wipe , then

Advanced Wipe and check the Dalvik Cache, Cache,

Data , and System boxes, then Swipe To Wipe .

Now tap the Home button to get back to the main

TWRP menu and tap the Install option. Select the ROM

you downloaded, then Swipe to Confirm Flash .

After swiping you will need to go through the AROMA

installer to finish the flash. The installer will have extra

options and tweaks that you can choose to add to your

device, but those are only needed if you plan on

keeping this ROM after flashing. Once the process

completes, select the Reboot option.

If your device doesn't boot as quickly as usually, don't

panic, that is expected. Once it boots back up, go

through the initial setup process one more time, as you

did when first got your phone. Once your phone is set

up you will need to reenable USB Debugging.

Plug your M8 to your computer and open up terminal.

You'll also want to download the S-Off tool Firewater

and place it on your Desktop.

1. Reboot your device using ADB.

adb reboot

2. Once rebooted, push Firewater to your device.

adb push Desktop/firewater /data/local/tmp

If you didn't put Firewater on your Desktop, you are

going to need to change it to the appropriate directory.

3. You'll now need to change the permissions of

Firewater so that it can run on your device.

abd shell

su

chmod 755 /data/local/tmp/firewater

After typing su , check your device to see if your

Superuser app asks for your approval.

4. Run Firewater, and do not touch your device after the

process starts.

/data/local/tmp/firewater

5. Now simply agree to the terms and conditions when

prompted by typing "yes", then let firewater start

chugging.

You're all set, your M8 is now S-Off!

Now you are all set to flash custom firmwares, radios,

hboots, and lock/unlock your bootloader at will. This

will also come in hand when you run into boot issues or

just need to return your One to factory settings. Be

sure to leave me a comment below if you run into and

issues.

for convertion to gpe--

Once you see the bootloader menu, type fastboot

reboot-bootloader to prevent any errors from coming

up.

Now, to get your device into RUU mode, type fastboot

oem rebootRUU , and you'll know you're in the right

place when you see a black screen with a silver HTC

logo.

With your device ready to go, you are going to need the

RUU, or ROM Update Utility, for the Google Play

Edition. A RUU is a recovery file that contains the

stock ROM, radio, firmware, and recovery that ships

with your phone—in the this case, it will contain all the

Google Play Edition stock files.

Grab either the rooted or unrooted version, and to start

flashing the file you selected, place it on your desktop

and type the following into ADB:

fastboot flash zip RUU-

HTC_One_M8_GE-4.4-3.62.1700.16.zip

Change the last part to RUU-

HTC_One_M8_GE-1.16.1700.16_rooted.zip if you are

installing the rooted version.

In the command prompt, you will see a line that reads

FAILED (remote: 90 hboot pre-update! please flush

image again immediately) , which is to be expected. To

continue, just re-run the same command as before:

fastboot flash zip RUU-

HTC_One_M8_GE-4.4-3.62.1700.16.zip

Again, change the last part if you are flashing the

rooted version.

Once the flashing has begun, you will see a progress

bar appear under the HTC logo on your device, and

terminal will display the progress as well.

When flashing is complete, you will need to wipe the

cache to prevent boot-loops, and reboot your system.

fastboot erase cache

fastboot reboot

Your device will now reboot, and you will need to go

through the setup process as if you were turning your

phone on for the first time. After the process

completes, you will be ready to go with a completely

stock version of Android running on your M8, with the

added bonus of perks like Duo Camera and

BoomSound.