LG Optimus G 4G LTE E977 gets the Nitrogen OS which updates the device to Android Marshmallow. This is unofficial update developed by the developer at XDA. This Nitrogen OS has many advanced and amazing features that are not given by the official firmware.LG Optimus G

So, once you flash this custom ROM on your LG device you can tweak your device as you like it. But to do so you need to have root access on your device and also have a custom recovery installed on it to flash the OS. Without root you can install custom or third-party apps on your device.

So, if your device fulfill all this requirements then you can go ahead and flash the ROM on your device. But note that once you flash the ROM you void your device warranty and also keep in mind that flashing of this custom ROM is at your own risk.

Preparing your Phone

  • This instructions are meant for LG Optimus G 4G LTE E977 only, do not try it on other devices.
  • Device should be fully charged up to 100%
  • Install device USB drivers on your PC.
  • Back up all the necessary data to external storage restore it later.
  • Make a Nandroid back up of the current ROM.
  • Device should be rooted and it’s bootloader must be unlocked.
  • Custom Recovery like TWRP should be installed on the device.
  • Enable USB debugging mode. Go to Settings > Developer options > USB debugging mode.USB Debugging

Download and Update LG Optimus G 4G LTE to Android Marshmallow

  1. Download the Android Marshmallow based Nitrogen OS for LG Optimus G 4G LTE along with Google apps from here.
  2. You can also try open google apps, to download the Google App’s visit the link here.
  3. Transfer the files to device storage and turn it off.Disconnect the device and turn it off completely.
  4. Reboot the device into recovery mode, press and hold Volume Down + Power key for few seconds.
  5. When in recovery mode tap on Wipe tab and select all the options given under it.
  6. Now, confirm the wipe action by swiping the button at the bottom of the screen.
  7. Now, return to main menu and tap on Install tab.
  8. Locate the ROM file stored on you 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.
  11. Return to main menu and tap on Reboot.
  12. System will now reboot in normal mode.

That’s all, device is now updated to the latest Android Marshmallow, you can check the Android version in Settings > About device > Android version.