You need the piston wind back tool.Back off hbrake cble and remove from calipers.manually pull the calipers lever as far back as possible(usually seized so drown in wd40)now,remove calipers and unseize sliding pins.peel back piston rubber boot and dribble some brake fluid onto piston,using windback tool move pistons FULLY back into calipers.fit new pads and sliding pins with copperslip grease.refit calipers ,now,using the caliper hand brake lever on the body manually opperate it untill the pads touch the disc.i usually clamp molegrips on the lever for better leverage.refit hand brake cable and adjust freeplay to4-5 clicks.sounds more complex than it is buti find that they have usually been buggered around with to the point where the levers never return to off position.and so the self adjuster ratchets never engage.
caine, July 2008