Not with Avid's but shimano and clarks there pretty simple as long you dont nic the new seals putting them back in so they don't leak, Its just the "rigmarole" cant spell" of bleeding them properly once rebuilt. If the pistons are rusty to try using the likes of some wet and dry sand paper softly just to make them a little smoother. "Bring on the comments of never touch a piston with sand paper" If you manage to have a go let me and others know what they are like to work on.
Isn't too difficult to do. The difficult bits are:
Getting the old pistons out. I put the car compressor with airbed attachment in one side, pumped up to 300psi while holding my thumb over the other hole and waited a minute or two for it to pop out :: Bleeding the brakes afterwards like you said, as you put a massive air bubble into the caliper when you put the piston back in.
I didn't have any problems with the seals. The old ones were a bit tricky to get out but the new ones just went in.
The old pistons were well and truly stuck and one was hardly moving outwards at all so the rebuild was worth it (£10 for the parts).
I bought the bleed kit as it makes life so much easier using the 2 syringes with the lock offs, allows you to bleed from both the caliper and master cylinder as Avids are a pain to get all the air out tof the system.