[Acexxon]

Here's the guide to open up the rear bumper:

Remove the screws first and there's one TORX bolt hiding in there as well : "8mm for all screws, 15 torx for the one screw that connects the bumper to rear fender"

After that, just pull the bumper outward gently.

You can do it without removing the wheel, but it is easier if you jack the car up on the side that you are working on.

The hard part is the 3 three clips in the back, I find it easier to press the clips with fingers... because you have to press and push outward at the same time.