[HOWTO] Convert your Optimus G to a Nexus 4 and Back

First off, there are a few issues.
-SDCard doesn't work.
-Capacitive buttons aren't working. No known way to fix it.


First off, lets flash the N4 Rom.

1) Install LGNPST - Use tSilenzio's AutoLGNPST - http://www.oudhitsquad.com/android/LGE/Firmware/Tools/AutoLGNPST-tSilenzio.zip
2) Download the Nexus 4 Image - https://www.androidfilehost.com/?fid=9390248398092765463
3) Rename the extracted .tot file to a .bin file
4) Put the phone in Download mode. Volume Up + Volume Down While inserting USB cable.
5) Open LGNPST and select the phone - Should be Com[Number]
6) In the DLL section, select LGNPST_LS970.dll
7) In the file selection, select the previously renamed Nexus 4 bin file.
8) Start the flashing process and hold your breath.
9) When it hits 67%, your phone should start booting. DO NOT UNPLUG YET.
10) At 85%, an error will occur saying that the phone was unplugged. Ignore it and close LGNPST. The image is fully flashed.
11) Hold Volume Up + Power to put the phone into FASTBOOT mode.
12) Download the recovery from here and place it into your fastboot directory. - http://xdaforums.com/showthread.php?t=2010984
13) Download the following 3 files and place them on the MicroSD card. - http://d-h.st/cFA - http://d-h.st/yUQ - http://d-h.st/0dH
14) While still in fastboot, type "fastboot boot recovery.img" - This will put the phone on the custom recovery. Make sure the SD card is in.
---Here, we're going to fix the partition tables for 16GB of space and replace the backup GPT so that we can't hardbrick from the backup GPT.
15) Run adb shell to get into a root shell in recovery.
16) Copy the modified DD onto the phone
17) Backup the partition tables incase something goes wrong.
18) Unmount the filesystems so that you can overwrite the partition table.
19) Make sure nothing is mounted. It should return this (Other than partition size):
20) Move the partitions to their new locations. This may take a couple minutes.
21) Install the new partition tables.
22) Make sure no errors occurred. Run 'parted /dev/block/mmcblk0' and check that it returns the same as the below.

23) If something different was returned, run the below code to restore the previous partition tables.

24) Exit the shell and type 'adb reboot bootloader' or reboot the phone while holding Volume Up.
25) Check that you're in fastboot mode and exit the following commands - This will fix the filesystem to take up the entire partition.

26) Boot the phone and update as needed. Then, put this on the phone and flash in recovery.
27) You are now working other than the SD card and Capacitive buttons.
Credits:
http://xdaforums.com/showthread.php?t=2117576
http://xdaforums.com/showthread.php?t=2099784
http://xdaforums.com/showthread.php?t=2160124
http://xdaforums.com/showthread.php?t=2146816

1) Wipe the phone. Go into fastboot mode [Vol Up + Power] and execute the following commands. This is to prevent corrupted data partitions.

2) LGNPST back to stock. You will do this twice to fix some issues.
To get into download mode, turn the phone off and hold Vol Up + Vol Down while inserting the USB cable.
3) Download these 2 images. Mar. 8, 2013 and Sept. 29, 2012
4) Flash the Mar. 8, 2013 firmware in LGNPST (See above for how to flash firmware in LGNPST. As before, the phone will start booting at 67% and LGNPST will show an error at 85%. Ignore the error and close LGNPST.
5) Restart the phone in download mode and now flash the Sept. 29, 2012 firmware. If you don't, your /SDCARD may be corrupted and you cant root.
6) Root the phone and unlock the bootloader. See here
7) If that doesn't work, try Teenybin.
8) Some partitions are broken. Go into CWM recovery and open an 'adb shell'.
9) Execute the following code. This will backup the broken partitions and wipe them.

---You should now be back to stock--- LGNPST again if you want 'True Stock'