Remove the old brake pads. Select the proper adapter and install it on the 3/8" square end of the pusher screw. Place the tool in the caliper. Squeeze the tool handle until the backing plate pushes against the caliper and the adapter and its pins seat against the piston. Use a 9/16" wrench or ratchet and 9/16" socket to turn the shaft until the piston bottoms in its bore. Continue squeezing the tool handle while turning the shaft to keep the adapter seated on the piston.