if your brakes are like the ones on my '89 240 (and I'm sure they are), you don't have to disassemble the caliper at all.... just use use a C-clamp or large channel-lock pliers to force the existing brake pad backing plates away from the rotor (to push the pistons into the calipers), then drive out the two pins that hold the backing plates in place. The plates (and remaining pads) will slide out. Replace with the new ones, slip them back into place (always harder than it sounds), fit the pins and the springs back into place, and that's it! Caliper stays intact, although I always find it a good idea to get a friend to help me go thru bleeding the brake lines every year or two, just so there's fresh fluid in the system to prevent corrosion....