Wiggle the caliper out and off of the pads/rotor, and place out of the way - do not let it dangle by the brake hose.

Use the brake spreader tool on the front or the caliper wind back tool on the rear to push the piston back into the caliper for assembly.

Pay close attention that the hose is not twisted when re-installing (flip caliper as necessary to remove twists). A twisted hose will overheat the brakes, causing damage and a reduction or loss of braking performance.