I have had mine off a few times (I have custom carbon ones not the Audi ones)
If you look at the new ones you will see how they are attached. its basically a few orange plastic clips that push into the body and then a couple of white clips from memory which tend to break.
It just takes a bit of brute force to get them off, start at the door end and pop the clips out the holes then just pull hard has been the method I've used. They have a strip of double sided tape from factory down the back edge next to the boot opening.
If you want the official Audi method you can download the workshop manual on
https://erwin.audi.com/erwin/showHome.do but it will cost you for an hours use.