Yes, it's a reasonable job for a shade tree mechanic. Did mine about 3 years
ago ('83 911SC).
I used this very good article (and dug it back up for you)
http://www.pelicanparts.com/techarticles/911_caliper_rebuild/911_caliper_rebuild.htm

I used Scotch-Brite (scouring pads) on the bores and pistons (they were
rusted) with carb cleaner until I couldn't get them any cleaner.
Had the rebuild kits already on hand (piston seal and rubber bellows).
If you get any pulsing when you stop, go ahead and replace the rotors, too.
(all 4 were only about $200 for me)
I'd go ahead and plan to replace your rubber brake lines while you are at
it. You can use either the stainless steel braided or OEM rubber lines (I
chose the OEM rubber) If you go SS, just make sure they are DOT certified
and of good quality (costs a little more)
Have about 2 qts of DOT3 brake fluid on hand and with regards to bleeding
start with the right rear, left rear, right front, left front. Best done
with 2ppl (one to press the brake, the other to tighten/loosen the bleeder)
or a pressure bleeder (about $40)
Tap the calipers after you think they're bled (air bubbles get trapped) .
You will be well rewarded for a job well done. It is amazing how much better
it stops now.
Good luck.