sharing my experience on reverting my G2 F320S back to stock firmware as it was unrooted and flashed to a custom Chinese ROM when I got it:
- refer to this link to download the stock firmware and the necessary tools:
http://forum.xda-developers.com/showthread.php?t=2432476- ran into trouble after reverting to the stock firmware - phone keeps on complaining com.android.phone process has stopped. after a few times, the phone will restart itself
- the key to successful revert to stock is to hard reset the phone after that but it was challenging as the phone keeps on resetting
- supposingly for the korean version, you can also hard reset by pressing the Vol Up + Down + Power button simultaneously and holding them until a korean menu came up with 3 selection and you choose 1 using the up down button at the back. It's all in Korean and Google Translate doesn't help, but none of those 3 selection works
- managed to prevent the phone from restarting by switching it to airplane mode but the same error message appears
- managed to get the phone into English mode and did factory reset.
After that did OTA software update from 10M to 11C (~80MB). Can also update using LG PC Suite but doesn't seem to be able to download the update.
Happy camper now with tons of Korean apps, some doesn't work without the SK Telecom uSIM card.
Also got Q-voice (voice command i think, haven't tried it out yet)
And most importantly wifi storage is now working (previously it always crashed on that custom chinese ROM). With Wifi storage, your phone behaves like a network drive