ive got a spare rear caipler in my house that i can take some pics of to show you where the bolts are.

in total theres 4 bolts, 2 hold the caipler to the caipler holder and 2 hold the caipler holder to the hub. if your getting one from the scrap yard you have to undo the two that hold the caipler holder to the hub but if your getting a recon caipler you need to undo the first two that hold the caipler to the caipler holder.

quick step by step

1 first you'll want to get a set of mole grips on the brake line.
2 then you want to undo the brake line from the caipler just abit to get it lose.
3 then undo the top two bolts.
4 then pull the caipler up and push towards the car.
5 then with the caipler off disc push it towards the front of the car and lift the cable of the caipler and then twist the caipler around to get the brake line off.

refitting is just the reverse of the above starting with the brake line then handbrake cable then fitting the caipler back on. [Note] if your buying a second hand caipler from the scrap yard then dont forget to wind the piston back in.