Do you own an LG G3 and want to install custom ROMs and all sorts of hacks on it? If yes, then you will need to unlock LG G3 and install TWRP, a custom recovery that opens doors for third party firmwares. To use this TWRP, you must be rooted already. Also, you will need a working ADB installation on your computer.
Here is how you install TWRP and unlock LG G3.
Download the file from here to your computer
Set your phone to MTP mode, and copy the downloaded file to your phone’s INTERNAL SD Card
Open a command prompt window on your computer, and run these commands one at a time
adb shell
su
dd if=/dev/zero of=/dev/block/platform/msm_sdcc.1/by-name/recovery
dd if=/sdcard/twrp-2.8.0.0_CHANGEME-signed.img of=/dev/block/platform/msm_sdcc.1/by-name/recovery
Easy, right? You can now get into recovery as follows:
Power off the phone, and unplug USB
Hold Volume Down + Power
When you see the LG logo, keep holding Volume Down, release Power and quickly press it again.
Continue holding both Volume Down and Power until you see the “Factory Reset” screen
Press Volume Down, then Power to confirm
Press Volume Down again, and Power to confirm once again