hi there you dont say what the vehicle is?
yes you will have to remove the caliper to remove the discs.
few thins to know:
1)always replace the brake pads at the same time (new set)
2)when you remove the caliper tie it up with string to the spring so it doesnt put any strain on the flexi hose
3) always clean the oil form the new disc prior to fitting you can get a can of spray degreaser for a few quid from any car accessory shop.
4) make sure before you remove the caliper that you push the pistons right back so you have room for the new pads just makes it quicker and easier.
if you're on uneven ground apply the hand brake tight and chock the rear wheels.
after removing the wheel remove the brake pads, then push the pistons right back then remove the 2 bolts from the rear of the caliper, tie it up.
remove the disc make sure you clean the new one and fit new pads.
hope this helps
simonvann@hotmail.co.uk
simon
February 2009