Here is the information to replace the pads:
Sorry I forgot to send the install instructions!! You need to turn the piston in not push it in.
INSTALLATION NOTE: Perform STEP 1 through STEP 6 on each side of vehicle to complete pad set installation, then proceed to STEP 7. CAUTION: Anytime the brake rotor or brake pads are being replaced, the rear caliper piston must be seated (bottomed) to compensate for the new brake rotor or lining. Because the parking brake self-adjuster mechanism is attached to the piston, a special seating method is required. The only acceptable method is by rotating the piston back into the bore using Retractor, Special Tool 8807, as described below. Any other seating method will damage the self-adjuster mechanism.