Not too bad a job, but I have to beg to differ with the other response on a few things. Never hang a caliper from its hoses. Just take a coat hanger and bend it such that you can hook the caliper to the coil spring without putting stress on the lines. Actually, it might be okay to hang it from the hoses, but why run the risk of making a fairly easy job in to a nightmare in which you have to replace a torn brake line or drill out a broken fitting, then bleed the brakes?

The caliper mounting bolts may be frozen. I blew out two sockets and bent a box wrench trying to get mine out the other day, and finally had to take it to a shop to have them loosened and retorqued so I could do the rest of the job myself. Volvo was (is?) in the habit of using red threadlock on everything, and the stuff really does its job.

As far as the actual removal of the rotor, after you have the caliper hung out of the way, the hardest part may be getting the rotor itself off. A little rust goes a long way, here, but so does a three-pound sledge. If you bear two things in mind, 1. that the suspension is designed to have a 3000 pound car bouncing all over it, so it can take a bit of a beating, and 2. that you won't be re-using the old rotors, this part of the job can actually be pretty fun. Whack away at the center of the rotor with wild abandon. Tap on the face of the center of the rotor. Even hit the edge of the rotor, if you think it will help. You probably don't want to hit the face of the rotor, though, as I would think it might shatter, and that would probably be bad.

Good luck, and have fun,
-EdM.
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'90 240DL Wagon 'Lola' -- '72 1800ES 'Galadriel'