20 to 30-minute job to replace the brake light switch. It's more difficult to remove the panel under the dash than it is to replace the switch. 1/4 turn clockwise, pull switch out, unplug from harness, ensure central plunger is pulled all the way out on the new switch (not collapsed to minimum position), connect to harness, insert in mount and rotate 1/4 turn counter-clockwise, reinstall panel.
Panel has screws and clips; you'll need to remove the screw for the hood release latch. IIRC, the OBD2 connector is released by pulling a plastic collar to one side. Some photos here to give you an idea prior to going in:
https://www.benzworld.org/threads/ch...panel.3035719/
Internet search on W210 brake light switch replacement.