AT&T LG Optimus G E970 gets the Nitrogen OS based custom ROM to update the device to Android 6.0.1 Marshmallow. This is unofficial Android Marshmallow update from the Android developers. To flash this ROM on your AT&T LG Optimus G you first need to root your device and install a custom recovery on it.LG Optimus G

This ROM has brought in with many advanced features which are not available in the official firmware from Google. As the ROM is in the development stage you may face some problems with few ROM functions. As the future builds are released the ROM will get stable.

So, to flash this ROM without any error we have given simple procedure below with download link for ROM and Google apps given in it. Follow it carefully to avoid any damage to your device. If anything goes wrong you are the only person responsible.

Preparing your Phone

  • This instructions are only for AT&T LG Optimus G E970 device, do not try it on other device or you may brick your device. .
  • Device should be fully charged up to 100%.
  • Backup all the important data to some external storage.
  • USB drivers for device should be installed on the PC.
  • Make a Nandroid backup of the current ROM in case you wish to restore it.
  • Device should be rooted and its bootloader must be unlocked.
  • USB debugging mode should be enabled. Go to Settings > Developer options > USB debugging mode.USB Debugging

Install Marshmallow Nitrogen OS on AT&T LG Optimus G E970

  1. Download Android Marshmallow based Nitrogen OS custom ROM and Google App’s from here.
  2. Download Android Marshmallow Open Google App’s from here.
  3. Connect the phone to computer and transfer the ROM and Google App’s file to your device internal storage.
  4. Disconnect the device and turn it off completely.
  5. Reboot the device into recovery mode, press and hold Volume Down + Power key for few seconds.
  6. When in recovery mode tap on Wipe tab and select the options you like to wipe.
  7. Now, confirm the wipe action by swiping the button on the screen.
  8. Now, return to main menu and tap on Install tab then navigate to ROM file stored in your internal storage of your device and select it.
  9. Swipe the button at the bottom to flash the ROM file on your device.
  10. In the same way flash the Google App’s on your device (step 8-9).
  11. Return to main menu and tap on Reboot.

That’s all you can now check the device Android version in Settings > About device > Android version.