If you are uncomforatable doing the troubleshooting and repairs yourself I would take the car to a independent MB repair shop.
If you are feeling like you can venture out and fix this one your self I have provided the information to get you a good start below.
I pulled this from the service manual available for download from this forum from the link I provided below. Please follow up with us so we all may learn what you find.
https://www.crossfireforum.org/forum...ollection.html
Starting on 8L-129 has the troubleshooting steps. 8L-149 has the below steps for removal.
REMOVAL
1. Disconnect the negative battery cable.
2. Using a trim stick (1), gently pry down and away
from the courtesy lamp switch/unit body (2) to
release the lens cover.
ZH LAMPS/LIGHTING - INTERIOR - SERVICE INFORMATION 8L - 149
3. Remove the retaining screws.
4. Using a trim stick, gently pry and lower the courtesy
lamp switch/unit from the headliner opening.
5. Disconnect the courtesy lamp switch/unit harness
connector and remove from the vehicle.
INSTALLATION
1. Connect the courtesy lamp switch/unit harness
connector (1) and align into the headliner opening.
2. Install the retaining screws and secure.
3. Install the lens cover into the courtesy lamp switch/
unit body.
4. Connect the negative battery cable.