did all 4 corners on mine in about 2 hours, rears wil give you the most hassle, you will have probs getting the wheel bearings out the disc as this is where they are so buy new ones, they are a right pain to get into the new disc without damaging them, they really are a pain but do able, its just very tight fit, you will also need new lock pins (can get them at halfords for pence) and you will need a lock washer for each side unless your are mint which i doubt, these are about a quid at the dealers.
wheel bearings are about 12 to 15 quid per side
its a faffy job getting the rear calipers in bits if you aint ever done it before... you need a good set of alen keys too, you will see what i mean

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and the most inportant thing of all, you will need the caliper wind back tool, without this you will NOT finish the job, these are arount 15 quid at halfords, made by a company called Lazer..