I'm replacing the front brakes pads on a 1990 Subaru Loyale with a 1.8 Litre, 4 cylinder engine with about 138,000 miles on it. I got the new pads in place but I cannot seem to get the piston to go back into the caliper. I've tried a C clamp, but it won't budge. The Chilton's book says to " Use an appropriate tool to rotate the piston into the caliper", whatever that means. Any suggestions?