Hello guys, I'm new at this site, so please correct me if I'm wrong, please!!!

My problem:
I have a e60 530d with a proffessional version of the navigation. Problem is that between the housing and the screen the rubber foam is coming down. At this moment it is not that much, but I already notice that this rubber foam is already partly covering some caracters on the screen. I would like to take out the unit and fit the rubber properly as it should. Taking out the unit is no problem as I already found on the site, but dismantling the unit till the point I can refitt the foam is something I can not find right away. Can please someone tell or show me how to do this? I will add a picture of the actual situation below.
Many thanks in advance,
Rudy