bklyn, I didn't replace mine but had to disconnect the inside boot to replace my rear shocks. If you separate the wheel carrier from the wishbone without loosening the eccentric bolt then theoretically you wouldn't effect the camber. Here's the problem, it's not easy to lift the carrier off the wishbone because the shock and spring are in the way. I ended up loosening the eccentric bolt and everything just drops.
When I did my shocks I marked the eccentric bolt and was able to get it back perfectly on one side...but on the other wasn't so lucky and had to get an alignment.
I think Wayne can jump in and correct me where I'm wrong here. I also found the following good link for front and back shocks that might be useful picture wise for you. I used Wayne's for the front but this link for the rears.
Boxster Hacks and Instructions