If you google enough, you'll find a how-to on rebuilding calipers.

Use compressed air to to pressurize the caliper to pop them out. The first one will be easy, but the second will be a little trickier since there's a big hole from the first piston. You can slightly put the free piston back in a tiny bit to close off the piston bore and then pressurize the caliper to pop the second piston.

Andrew Lee
'00 S4
'93 Civic: Honda Challenge #27
'05 Ram 2500

Brakeswap, where I get my brake pads and rotors

Some of my race videos