actually, you don'at always have to take the caliper off. Just make sure you use something "soft", like wood, to press on the parts. You can push the pistons back in carefully.do you have to take the caliper off the rotor to push the piston back in and how do you push the piston down ?
Do you have the metal plates installed in the back of the brakepads? You can see them on this pic:AMke sure you put some grease on the back of the pads. I forgot to grease one for my rear and it always makes a damn squeak. Annoys the crap outta me.