-jack the back up
-take the wheels off
-2 m10 bolts in each wheel arch, at the back. one holds the bumper on, the other holds both the bumper & the arch liner iirc. closest to the outer edge of the arch
-2 m10 bolts underneath the car, near the centre of the bumper (under the boot basiaclly)
-2 torx bolts on the top of the bumper, just underneath where your bootlid closes. if you open your boot you'll see them
after all that is removed theere are afew clips on the side bits that connect to the arch, just pull the bumper away each side and they should unclip.
Make sure you have something soft & cleanish under it so if you drop it accidentaly, it wont scratch
also make sure you remember to disconnect the numberplate light before you pull the bumper off so you dont rip the wiring out
thats all i can think of atm, hope it helps!