easy a p*ss mate, dont pay a garage to do it. Theres the screws that you see when you lift the boot lid, then theres a few under the car, and 1 or 2 in the wheel arches. Changed my bumpers about 3 or 4 times, dont exactly remember where every screw is without going outside and taking a look (its cold), but theres a simple method.
1: loosen all the screws you can see
2: move the bumper around to see where it is still hooking (area's where screws are still in)
3: remove those remaining screws
4: pull of bumber
and e viola
simple as simpleness