It's a big, fat PITA too. I hate doing the rear pads these cars. Somebody may have a simpler way, but I take the caliper and cradle off, remove the rotor, put the cradle and caliper back on, and use the tool and a ratchet with a 4" extension to crank the piston in. Every Ford vehicle I've ever had with rear disc brakes have had those "twist-in" caliper pistons. Even my old '87 and '88 T-Bird Turbo Coupes had them.