haha yeah when i was changing my brake pads I was using a c-clamp to try and push the piston back in. i tightened that thing as much as i could and the piston wasn't budging. i finally checked the fsm and found out that it was threaded. this was the first caliper i had ever seen set up like that. when you are gripping the notches with the plyers, make sure you have a good grip on it when turning because the plyers can slip off and scratch the piston.... i did it a couple times. it also requires a bit of force to turn the piston, but it will turn.