Uh.....why? If the calipers aren't seized up you should be able to pop the pistons out with the brake pedal or with compressed air. They should come right out without having to reinvent the wheel.

If your pistons are that stuck, use the calipers as cores and get rebuilt ones. You'll be money, time, and frustration WAY ahead.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]