HI
first release the park brake and press the park brake down and turn the ignition off and pull the key out, park brake will stay off now
remove the rear caliper and pads, the wind the piston back with a tool like ralphs picture above
refit discs, pads and caliper, you might want to adjust the piston on the caliper, so the caliper fits on snug, no large amount of play, but not too tight it binds
the you need to disconnect the battery and reconnect, you will get a message now saying apply the parking brake, press the brake pedal a few times so its hard, the apply the EPB
and thats it
cheers
Joe