Agree that's how I do it.You can blow the piston out using compressed air too, if you have it.
Tony.
If it's that tight, and you don't have compressed air you may need to re attach the hose and pump the piston out.Caliper is off. Piston is well and truly seized in. Pulled the seal off but not quite enough angle to hit the piston indent ring with screwdriver and hammer to free up.
Apologies for the running commentary! Managed to free up piston by winding it back it the using a brake wind back tool then freeing it up a bit with water pump pliers. Still not out.If it's that tight, and you don't have compressed air you may need to re attach the hose and pump the piston out.
Tony.