Rear brakes

[Zip]

2010 RSS

I have Ron's pads, no matter what I do I cannot get the
Piston to retract enough to fit them on. I spoke to Ron and he said I am doing everything correct. They are not screw in. I bent a C clamp trying to move them. I tried WD40, I tried tapping with a mallet but it only goes so far. I am missing by like a 1/16 inch.

Any ideas from the collective minds of SL?
Thank you in advance.