How do I remove rear bumper cover on a b4 passat?

Hey everyone, I am trying to install my new trailler hitch and I need to remove the rear bumper cover to drill some holes. I have removed every screw and bolt that holds the rear bumper cover on but I still cannot get it off. The sides are loose but it seems the clips on the back are still very difficult to get it off. So how can I remove it without damaging it? Any advice is greatly appreciated!

There's a couple of bolts in the trunk under the tire cover. Remove them and slide it out.

Remove the skin and the internal aluminum bumper as one piece, it's much easier that way.
Four bolts in the trunk along the sides, and some clips or screws holding the skin at the wheel arch.

anyone have the part number for the clips...?