Ford: rear disc brakes, rear disc brakes, parking brake cable

Question
1997 Sable with ABS disc brakes, what is the procedure to retract the rear brake pistons to install new pads? I've tried to rotate the piston both clockwise and counter clockwise, they will spin but will not retract back into the calipers. I don't see any way to unhook the parking brake cable or the lever to allow it to rotate backwards as is done with Cadillac brakes.  

Answer
if the calp. has notches  the  in it then the only way to retrack the pistion back is clockwise if it won't then try to loosen the bleeder see if that helps.remember you have to turn the pistion and push back at the same time. let me know what happens