H811 is the T-Mobile variant of the LG G4 released in the US. LG has been pretty good at releasing Marshmallow updates for its flagship devices, including the LG G4. LG has started rolling the 20i Marshmallow update to LG G4 handsets in the US.

The best way to get the Marshmallow update on your T-Mobile LG G4 is to update through OTA. But if you are rooted or have modified the system, then you won’t be able to update to Marshmallow. There are a few alternatives to installing Android 6.0 in this case. You can install a custom recovery and flash a flashable 20i Marshmallow zip file or you can flash the KDZ file.

Both are great options to update your T-Mobile LG G4 H811 to Android 6.0 Marshmallow. Follow the section below to grab all the required files and learn how to install the Marshmallow update.

How To Install 20i Marshmallow ROM on T-Mobile LG G4 H811

H811 Marshmallow ROM (link)

TWRP recovery (install)

How to install Marshmallow ROM on H811

Move the Marshmallow ROM (LG-H81120i-Flashable.COMPLETE.zip) from your computer to your phone. Turn the phone off and go to recovery mode. In this case TWRP will appear. You need to backup all the current partitions including boot, system, data and efs. Then you need to wipe data before flashing the ROM. Go to Install > Select zip and select the Marshmallow ROM. The swipe to confirm/flash.

Now the phone will reboot and in a few minutes your T-Mobile LG G4 H811 will be running on Android 6.0 Marshmallow. Alternatively, you can also download the KDZ file and flash it if you don’t want to use a custom recovery.