A Mercedes C230 radio is held in place with locking tabs inside the dash. If you want to replace it, you'll need to know how to unlock the radio. You should always have the radio code before attempting to remove the radio and replace it with a new one; otherwise, you will not be able to use it. Mercedes uses specialized DIN removal tools that you can purchase from the company. This is the only way you'll be able to take the radio out of the dash.
Disconnect the cable from the negative battery terminal. Loosen the nut on the cable clamp until the clamp can be slid off the terminal.
Slide a DIN tool into each of the openings (there are two) on the face of the radio until they click and lock into place.
Pull the DIN tools out away from the dash and the radio will come out with it.
Disconnect the antenna and electrical connections from the back of the radio.
Plug the antenna and electrical connections into the new radio and install into the dash. Installation is the reverse of removal.
Reconnect the cable to the negative battery terminal.
