For those of you who may soft-brick your LG G3 (soft-brick is when you are stuck in a bootloop), want to return your phone back for warranty, or simply want to return back to 100% stock, here’s a step-by-step tutorial you can use.
First, you will need a Windows computer as LG Flashtool program does not support other operating systems. (You may be able to use VMWare on Mac or Linux, it should work.) This should work on all Windows including Windows XP, Windows 7, Window 8, and Windows 8.1. (I am using Windows 7 64-bit, I just don’t like Windows 8 that much.)