So long as your LG G3 device is not already rooted and is running stock firmware, you will be getting an official Android 6.0 Marshmallow notification arriving over the air in the coming days if not already. Once you accept that notification and update your G3 handset to the latest version or Android, you might be wanting to get root access so you can start customizing your smartphone once again.

These are the guidelines to root LG G3 D855 on Android 6.0 Marshmallow. Try updating to that same software version before following this guide for best results.

REQUIREMENTS

• You must be running the aforementioned Android 6.0 on your G3 before attempting to follow this steps.
• You must have a custom recovery installed on the LG G3 with model number D855 before you can complete this guide.

BEFORE WE BEGIN

• Since you will be connecting to the computer to use the guide, you will need the USB Debugging Mode enabled — you can do that from the settings; just head to the Menu > Settings > About Device and tap where it says the firmware build number roughly seven times. You can easily tell when it’s unlocked by reading you are now a developer from the display.
• Moreover, now that the Developer Options menu is officially unlocked, you can enter that menu. Head to the Menu > Settings > Developer Options and check the box for the USB Debugging Mode.
• Those of you who did not follow the steps above might be lucky enough to get an “allow USB Debugging” notification after connecting the LG G3 to the computer using the USB cable.
• You are voiding the G3 warranty by following this guide. You can flash the stock ROM back on your device later and it will revoke the root access and remove the custom recovery. By doing that, your warranty should work once again.

HOW TO ROOT LG G3 D855 RUNNING ANDROID 6.0 MARSHMALLOW

1. Download the updated SuperSU from this link.
2. Connect the LG G3 to the computer using the USB cable.
3. Copy the SuperSU over to the root of the D855 SD card internal storage.
4. Unplug the G3 now from the computer.
5. Choose to boot your D855 handset into the custom recovery mode you should have installed earlier as part of the prerequisites.
6. Tap on the ‘Install’ option from the recovery mode menu and browse the SD card for that same SuperSU file you transferred there earlier.
7. Swipe to confirm you want to install that SuperSU on your G3 device by swiping over that same option that is available on the bottom of your display.
8. Once the SuperSU is installed, go back to the main recovery menu and choose the ‘Reboot System’ option from the menu.

Now your G3 D855 handset will reboot back up in normal mode and you are ready to take advantage of having that same root access on your device.