Android 6.0 for T-Mobile LG G3 (D851) finally released via OTA after formerly only available via the LG PC Suite. You should be able to get an update notification now, but you can always force to check the update via the main settings. The good thing is, the bootloader still unlocked even though we still don’t have access to the bootloader or fastboot mode. With unlocked bootloader you have an opportunity to regain full root access on Marshmallow for T-Mobile LG G3.
This Marshmallow OTA comes with D85130d software version, and this is the sixth official update that has been received by this phone. The Android 6.0 could be the last major update for this device, since the phone was released two years ago, so do not expect to get official Android N. However, this does not apply to those who already have a custom recovery (TWRP) installed, since these people can update their phone OS at any time with a custom or unofficial ROM.
In order to install the downloaded OTA update, you are always suggested to restore the phone back to stock, to unroot and replace the custom recovery with the stock one. As you may know, to install an official software update, the phone system needs to be in stock condition, including the recovery, or the installation will be failed. But if you do not want to unroot the phone, you still have an easier and faster option by flashing a custom Marshmallow ROM via TWRP.
Regain root on Android 6.0 (D85130d) for T-Mobile LG G3 can be done with the help of one-click app called Kingroot, however, it’s only gives you temp root access. To gain full superuser privileges, you must take some additional steps, one of which requires you to install custom recovery and run multiple adb commands.
Here’s the overview on how to acquire full root access, adb knowledge is required to run this method:
- Download the latest USB drivers for LG G3 and install it on your computer.
- Grab the latest Kingroot app and install it on the phone.
- The open Kingroot app, then makes attempts to get temp root access.
- Get the latest stable TWRP image file (.img), flashable SuperSU (.zip) and a flashable boot file (.zip) and move into internal storage.
- Make sure you have adb on the computer and also enable USB debugging on the phone.
- Open Windows command prompt and run some dd commands.
- Reboot to TWRP, then backup Boot, System, Data, Efs (backing up everything is optional but it’s always recommended).
- Flash SuperSU and the flashable boot file (zip).
- Reboot and you should rooted now. For the complete step by step method and download the required files, just head to autoprime’s thread on xda-developers.