I've got my rear brakes apart and need to retract the piston, but I don't have the fancy schmanzy Audi too. Can someone give me the tip on how to do it with a C-clamp? Interestingly, one side of the rear had almost full pads, the other was down to the metal backing plate (Mintex Reds) Thanks! Lee '95.5 S6 avant '96 A6 quattro avant