Make sure you have a small bolt (forgot the size, but I think it's 8mm thread bolt. It's on the MKIV board) for the rear rotors. You take those rotors out by screwing in the bolt into the bolt holes (should be 2 small holes on either side of the center), if you can't pull them off.
Other than that, it's pretty easy. The biggest pain will be removing the caliper bolt. You need to remove one and loosen the other to drop the caliper to remove the rotor, but they're torqued on tight. Also, you'll need some way to pushing the piston back into the caliper before putting the caliper back onto the rotor. Otherwise, you won't be able to put the brake pads back in. It's not hard to do. Just takes a lot of pressure. I'd get something flat, and put that on the piston. Then squeeze hard. I know there's tools available for doing this, but I just removed my whole caliper and did it, since I was replacing the brake lines as well.