how do I compress the brake piston so I can slide the caliper over new pads? on 2008 Chevrolet Uplander

How do i compress the rear brake piston so I can slide the caliper over the new brake pads

Asked by for the 2008 Chevrolet Uplander
special tool turn or twist back inward,(don'tuse C-clamp)you will damage something.
1 more answer , 1 more comment
open your break fluid resovior get a big enough clamp and use your old break pad put the pad adgainst the pistion and take the clamp and put the top part of the clamp behind the caliper and the bottom part of the clamp adgainst the old pad and start closing the clamp until ur pistion is all the way closed install new break pads
The REAR wheel brake pistons MUST be turned/rotated back inward like a screw clockwise to move them inwards - one can use a large needle nose pliers or special tool from GM to do this. The 10" needle nose pliers worked fine for me.