Here is the official Android 4.0 Lollipop V10B and V10D firmware for LG G Flex 2. I’m pretty sure these firmware is already all around somewhere in the net, but here’s an original link to it. Just attached here to give you an one more choice to download it. Have a good day.
Surely, you can manually flash your LG G Flex 2 by using LG FlashTool. The flash guide is all over the web.
LG G Flex 2 Phone Photos – LG Cell Phone Pictures
LG Cell Phone Related Posts
How bout for Korean Variants?
i have F510L 09h