Of course if you are experienced with rooting this is not going to be an issue. One important thing is that owners do have flash stock OS build VS98012B. AutoPrime is needed to root the handset, but this isn’t all that hard.
When the LG G2 has been rooted, the bin file needs to be obtained and then renamed and added to the handset. It will need to be put in a separate folder. You will then be able to type in the commands through ADB.
Providing that you do this correctly the device will go through a long restart and then reboot. When it has finished the device will be running on stock KitKat.