Any time you work with the old plastic on a Mercedes you should be worried. It will crack and break. If you use caution, you can do this though.
The secret screw for the center wood is on the rear under the little piece of carpet.
As for the vents, there are 4 tabs that have to be released all at the same time.
1991 GMC Syclone
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM