The "rebuild" on the caliper consists of removing the pistons and prying out the piston seal, then installing a new seal and dust sheild after cleaning the pison and the bore in the caliper with brake parts cleaner. Unless the piston or bore is badly rusted or corroded, it is very simple.
You do need basic mechanical skills, and a source of compressed air for removing the pistons is nice (you can use a bicycle pump), but not completely necessary.
The only difficult parts are getting the piston in the caliper at the correct orientation -- there is a raised portion of the piston lip that sticks through the heat shield that must actually protude and the piston must go into the bore at a particular rotation. It's easy to get it aligned to start with, but sometimes you must apply considerable pressure with a piece of wood stuck through the throat of the caliper to get the piston to go back in, and it's very easy to rotate it accidentally. It isn't possible to rotate the piston once it's installed without the special tool (expanding pliers that fit in the hollow), so you must remove the piston and re-install it if it rotates. Not hard, but a pain. Getting the dust boot back on can be difficult, too as you cannot reach one side to tap it down.
The good part is that the only thing you can really screw up is cutting the piston seal during installation of the piston, and this will result in an instant leak, easy to see.
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!