[LG Optimus 2x] SREEPRAJAY:
A small guide for this great tool

First,

Thanks to @spyrosk for this excellent tool

Thanks to @bitdomo for this guide.

Thanks to @tonyp for the TWRP for the O2X

I have modified this guide with few small additions...for the Internal SD card fix and generally some tips

Check the post:

Go to this thread.

Download AIO-TOOLKIT.

Install AIO-TOOLKIT.

Remove the battery from your phone

Connect the USB cable to your phone while you are pressing volume up & down buttons.

If you haven't installed APX drivers before, then windows will notice a new hardware and it will try to install the drivers for it, but it will fail.

Start AIO-TOOLKIT.

If you already have APX drivers installed skip this step. If you don't have the APX drivers installed, then press "I" (capital i), After that a window will apear. Just follow the instruction.

In AIO-TOOLKIT at the Main menu press number 4.

On the next screen you can decide between the new and old pt layout and bootloader. Keep in mind that whatever you choose you have to flash the correct rom for the correct bootloader+partition layout. So the new MIUI roms are only for the new bootloader and layout, old miuis like the 2.7 is for old bootloader. Here in the developement forum you can find CM10.1 roms which are made for new and old bootloaders, you just have to download the correct one to your actual bootloader. So press number 1 or number 2

Whatever you choosed at the previous step, press number 1, unless you want to do dualboot (two type of andorid on your phone). If you want dualboot then press number 2 and follow the instructions on the screen.

On the next screen you have to choose between 3 cwm version. If you selected the new bootloader I recommend to use cwm 6.0.2.5 or twrp 2.5.0.0. If you choosed oldbootloader I recommend you to use cwm 5.0.2.8 or twrp 2.5.0.0.

On the next screen, after you choosed your custom recovery, type "ok" (without the " marks) and hit enter.

Now the phone is going to be reparititonated and etc... so your phone will work again.

After the flashing ended wait about 10-15 secs then unplug the usb cable.

Reinsert your battery, then turn on your device. It should boot up into the selected custom recovery. If it does not boot up into recovery then turn off your phone and turn it on again while you are pressing and holding volume_down and power button.

Enable usb mass storage in the cwm recovery then plug the usb cable back. Format the internal SDcard to FAT32 then copy the zip file of the selected rom you want to flash (like miui or cm)

Flash your preferred rom

Restart phone.

Done

If you are changing from old to new bootloader versions, you may have to do this Internal SD card fix with this tool. This will wipe the Interal card completely. Make a backup first.

When you are done with the SD card fix....you will not have any OS installed, so flash the ROM using the Ext SD Card or go to USB mount and copy your ROM in the SD Card.

Using TWRP , you can install the root if for some reason you loose it while flashing a ROM. Nevertheless, it does not mean that CWM or TWRP is better or bad....both have advantages and disadvantages.

It is better to wipe the dalvik and cache each time you are updating the same ROM, changing Kernels, themes.

The ROM developer / chef OP mostly strongly recommends to make a clean flashing to avoid a mess of the leftover from a previous ROM (CM ROMs to Stock or vice versa).

Dont forget to report issues with logs and not post weird description of a problem or post a case due to NOT READING OP.

Please be sensible and friendly....Developers are not here as employees, each one of them are working here with great amount of passion, commitment, pleasure and putting in an extra oridnary amount of hard work (they have their families, personal life) in their available free time. So, DONT ORDER or ASK FOR TARGET DATES.

EDIT: I have added this post to my signature for future support and help.