I did not pop out the pistons. tried to push back in by hand by pushing on the shoes, no go. I wish I had a big C clamp so I would not need to remove shoes
No, remove the shoes and then you should be able to push the pistons for the wheel cylinder in-and-out from side to side. If they are not free moving, then they will hang up and I would recommend replacing the wheel cylinders. I always cycle the pistons in the wheel cylinders to check for freeness when doing brakes...
As stated before, the shoes can expand outward and hang up on the outer ridge of the backing plates...