These are the steps to install XenonHD Android 5.1.1 Lollipop custom ROM on the LG G3 smartphone. The guide only works for the International variant of the LG G3 that comes with the model number D855. You must have a custom recovery — TWRP recovery, CWM recovery or Philz touch recovery — installed on your device before following this guide. You must access that custom recovery to flash the custom ROM. You cannot flash a custom ROM for a stock recovery.

Furthermore, there’s only one way to upgrade the G3 operating system to the latest Android 5.1.1 Lollipop and that’s by installing this XenonHD custom ROM. There is no official 5.1.1 Lollipop available at the moment.

LG G3

The Files You Need

  • Download the XenonHD stable ROM from this page.
  • Download the Google Gapps package from this page.
  • You must have a custom recovery pre-installed before following the guide. We are not installing a custom recovery during this guide.

Installing the XenonHD Android 5.1.1 Lollipop custom ROM on the LG G3 International D855

  1. Download the XenonHD custom ROM file and the Google stock apps to the desktop of a computer.
  2. Connect the International LG G34 to the same computer where the files are waiting.
  3. Copy and Paste the two files to the SD card. That’s the internal storage SD card.
  4. Once you have the files on the SD card, unplug the G3 from the computer.
  5. You must boot the G3 in the custom recovery mode. You can do that using the usual key combination, or by installing an app from the Google Play Store such as the Quick Boot app.
  6. Once you are in the recovery mode, navigate to the NANDroid option from the menu. Take the NANDroid backup now so you can restore the data later. You are about to wipe the ROM clean.
  7. Next up, navigate to the ‘wipe data/factory reset’ or ‘wipe’ depending on your recovery.
  8. Navigate to the ‘install’ option — the wording will vary depending on you choice of custom recovery. However, all options start with the word install and are easily identifiable.
  9. Browse the SD card for the Xenon custom ROM and confirm you wish to install the ROM.
  10. Tap your finger over the ‘install’ option again and this time install the Google Gapps package.
  11. Now your device should have the custom ROM and stock apps from Google working. All you need to do now is reboot the smartphone.
  12. Go back to the main recovery menu and choose the reboot system now option from the menu. Your device will reboot and you now are running the unofficial Android 5.1.1 Lollipop build.