Someone backed into the right front of our 2001 US version XK8. It required a repaint of the bumper cover and replacement of the headlight - fortunately covered by their insurance. When I got it back from the shop, the headlight was pointing too low and to the right. I was able to retrieve the bubble level from the old headlight as the new one did not have one. However, I do wonder if the level had to be set at the factory when manufactured to be accurate. There is no gauge for the left right movement on the light as has been pictured in other threads although my left side has one.
My primary question is that the horizontal adjustment mechanism is covered by a plastic cover and thus I can not access the small nut on the side to adjust the light. I have attached a photo (was hard to get my phone in there so the quality is not that good). I assume this cover should be removed, but it does not pull off easily so I do not want to break anything. Has anyone had any experience with this?

Thanks for your help.