Just did it last week. It wasnt that difficult. First the felt lining for the window has to be pulled. Then small cross headed screws are exposed.
Unscrew these and the u shaped channel detaches. There was glue behind, but the u shaped channel actually has some strength, it is not to delicate.
Now you see a second alu piece that is flat. It also has the same cross headed screws.
I marked where all the screws were before removing them, it makes reinstall much easier
There was also a line of sticky glue behind both parts, and between the car body. I slid a plastic knife in between. Worked well.
I just grabbed the parts and stuck em on the car for you , see pics.
Last pics show how all the holes line up.
Enjoy.