In order to flash a custom ROM on your AT&T LG G3, you’d need a custom recovery that can let you do that. Fortunately, TWRP is available for the aforesaid device and you can have it installed on your device in just a couple of minutes using the guide below.

Once TWRP is installed, you’ll be all set to enjoy many of the custom ROMs available out there for your device. So, here’s how you can do that:

CyanogenMod

Files You Need

1. Your LG G3 must be rooted before you can install a custom recovery on it. You can check out our how to root the LG G3 from AT&T tutorial to learn how you can gain root-access on your device.

2. This should only work on a Windows-based computer.

3. Get the LG USB Drivers installed on your computer, if you don’t already have them.

4. Download Minimal ADB to your computer. It’ll be used to execute commands on your device.

5. Download TWRP Recovery Image for the D850 to your computer. It is the custom recovery that will be installed on your device.

Installing a Custom Recovery on the LG G3 (AT&T)

1. Extract files from Minimal ADB to your computer by right-clicking on it and selecting Extract here.

2. Turn on USB debugging on your device by going to Menu->Settings->Developer options->USB debugging.

If you don’t see Developer options in your settings menu, please head to Menu->Settings->About phone and tap on Build number for about 7-8 times until it says you’re a developer. You should then be able to see the aforesaid option in your settings menu.

3. Connect your device to your computer using a USB cable.

4. Copy TWRP Recovery Image from your computer over to the internal SD card storage on your device. Make sure you don’t copy it to the external storage or it won’t work.

5. Open a CMD window where the ADB files are located. To do that, hold down Shift and right-click anywhere on your screen and select Open command window here.

6. When the CMD window launches, type in the following commands into it and press Enter. Make sure to replace RECOVERYNAME.img with the real name of the recovery image that you have downloaded.

adb shell
su
dd if=/dev/zero of=/dev/block/platform/msm_sdcc.1/by-name/recovery
dd if=/sdcard/RECOVERYNAME.img of=/dev/block/platform/msm_sdcc.1/by-name/recovery

7. Wait for it to install the recovery on your device.

8. When it’s done installing the recovery, reboot your device.

9. You’re all done!

Cheers! The TWRP Recovery has been successfully installed on your AT&T LG G3. You can reboot into the same using Quick Boot on your device.

Now go ahead and load up that beast with your favorite custom ROMs!