Yeah, the alternator pulley is the one that is hard to get to... the other is really easy, just the bolts are hard to loosen. For the alternator pulley, you have to have a t60 torx socket so you can hold it from turning while using an open end 28mm wrench to loosen it (or you can do it the other way around...). Then getting the new one on, you have even less space to tighten the nut back on.
For the other one, you just have to put all your weight into loosening them and maybe have something jammed so the pulley can't move, and when you put the new ones on, make sure that you put loctite on the bolts.
DogP