OK I have a N2 HU with a N2 brain and would like to update the NAV maps. I have been reading and search for two day a with no luck. I see alot of guys talking about turning N1 into N3 and N2 into N3 but I see no posts, telling how it's actually done. Do I need to modify my brain or do I just need the right disk? I did the motion bypass the first day I bought the car.