How do you reprogram your key fob on Mercedes?

To reprogram a key fob for a Mercedes, first, ensure you're inside the vehicle with all doors closed. Insert the key into the ignition and turn it to the "On" position without starting the engine. Press and hold the "Unlock" button on the key fob for about five seconds, then press the "Lock" button while still holding "Unlock." Release both buttons to complete the reprogramming process. If unsuccessful, consult your owner’s manual or a dealership for assistance.