I did almost the same work on the rear of my 300D. Granted the rears are easier and I bought new calipers rather than rebuild the old ones, but it took me an hour and a half in a parking lot, with hand tools. Way better than spending $650.

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.