Gears & Axles - replaceing wheelstuds on a 12 bolt

i have a moser 12 bolt what is needed to be done to replace and where do i get the studs

You need to first see if you need threaded wheelstuds or pressed in wheel studs. You can tell by looking at the studs where they pass through the axles. ARP makes wheel studs in all common sizes. Stock wheel studs for our cars are a 12 mm, and you need to know if you need 12 mm or 1/2 wheel studs, then figure out what length you want to go to. Bob

do i have to pull the axel out

i didn't have to pull the axle out to get mine out.

I would upgrade to 1/2" studs will you are at it. YOu will need to pull the axels and have them resized for the 1/2" studs. At your HP level it's a smart thing to do.