Don't know if you've ever done brakes before...don't disconnect brake line. Don't squeeze lever with caliper off. I use the old pad in place with a C-clamp to press pistons back into position. Make sure they both go back in evenly. If you push one piston in only, other one will pop out. If you've ever topped off fluid, fluid will spill out of reservoir as you press pistons back in. I loosen bleeder screw as pistons go back in, but you have to be very very careful not to allow any air to get in.
