2007 SL550, Schematic on how to replace 3rd brake light & headliner. on 2007 Mercedes-Benz SL550

There are no Visible screws or clips. I have the light asimbly but can't access under the headliner.

1 answer
Did you ever get answer to "how to replace 3rd brake light"? I've got to replace mine and looking for help.
Thanks
Taco Bob