Hi,
Basically, open the boot. Then take the 2 trim panels where the parcel shelf sits on, and the 2 17mm bolts which hold the rear belts into place in the boot (If it has these).
There are 2 nuts along the edge closest to you when you open the boot, along the bottom - One on each side. Unbolt both of these.
Take the trim off around the inside of the rear quarters on the inside of the boot. There are 2 10mm bolts which hold the sides of the bumper in on here - one on each side.
There are also 2 nuts which you have to get under the back of the car. These are parallel to those which where in the boot... but just underneath the car instead. Unbolt these two nuts.
Lastly, make sure you have unscrewed both the reflector, and the foglight... and it should come off.
-Elliot