It would help to know what chassis you are talking about. For any W123 series car, there are small oval covers that come out. Then you use a phillips and unscrew the screws. There are 3 of them. Then down by the parking brake petal, there is a plastic "screw" that just needs to be turned left or right 90 degs. and removed. There is also another one of these gray plastic "screws" on the console side of the panel.

__________________
1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
MBCA member