rear pistons

hey, iwas just wondering if any one could help me with getting my pistons to go back into the rear calipers.i am trying to change my pads and rotors but the pistons wont go back in i to the calipers i tried pushing with my fingers and even tried using a c-clamp but they won\'t budge the front pistons simply went in by pushing with my fingers,so if any one could give me some advice that would be great.  thanx

you have to turn in the rear pistons....they don\'t push in like the fronts.
rotate them clockwise to turn them in to make room for the new pads.  Might have to use needle nose pliars to put in the notches on the piston to get leverage to rotate them.