Default [NOOB] Update LG G2 D800 to Kitkat

I know this might be stupid question but I don't have any experience in flashing etc.

So I have LG G2 D800 with 4.2.2 Software version D80010q, I want to update it to kitkat.

Do I need to Root , install recovery or can I achieve it by download kitkat stock firmware and flash it with LG Flash tool?