im changing my rear brake pads and im using a C clamp which i used for the fronts yesterday to push the piston in and it worked easily but the rear piston is not moving at all. is it supposed to be done some other way or what?

 

Rear piston screws in, it doesn't push in. Try needle nosed pliers and turn it.

 

the rear calipers/actuators use a simultaneous "squishing" and rotating the piston in a clockwise direction. Most of the the time (and especially on cars as new as our) you can use needle nose pliers in the two little slots in the piston and push and turn the piston all the way in. Just make sure you don't damage or tear the dust boot for the piston.

 

as alley said, just use needle nose pliers and twist it in, it will turn really easy

 

theres a little tool you can use that attaches to a ratchet that does the job still a pita tho

 

Also, make sure you E brake is not on.