I just spent some time looking through the manual to find the how-to. Came up empty, probably there I just haven't located it. Not much help here though, the kick panels are about the only pieces I haven't pulled on the 560
I'm thinking you will have to remove the underdash and the hood release lever/cable before being able to work the panel out, not sure about the passenger side though. I do not recall seeing any screws at the bottom edge (under the front carpets). The door edge of the panel is likely to be situated under the trim piece.
Hope this helps some.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.