There are two bolts to undo, one is a 15 or 17mm the other is a torx bolt. I can't remember the size offhand, I think it was 8mm.
Under the bonnet! undo the top of the brake fluid reservoir. (place lots of rags under the bottle, to catch the fluid that might escape over the top. Brake fluid is corrosive)
First open up the calliper all the way (so that the new brake pads fit) to loosen and remove the brake pads. Then Tie the calliper to the coil spring (so as to not stress the brake pipe) remove the two bolts. That's it.
Some Peugeots have a handbrake that works like the old brake drums. The drum is inside the disc. To loosen the handbrake shoes, there's a rubber plug in the disc, pull it out using long nose pliers, place the hole at opposition to the calliper. Look through the hole (not easy) and you should see a ratchet wheel. With a screw flat end driver move the ratchet up to tighten or down to loosen the brake shoes.
REMEMBER to replace the brake fluid reservoir top.
Ray Carcel, February 2008