How do you re-set w211 e 320 key fob?

To reset the key fob for a Mercedes-Benz W211 E320, first, 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 10 seconds, then release it. Next, press the "Lock" button while still holding the "Unlock" button, then release both buttons. Finally, turn the ignition off and test the key fob to ensure it is functioning properly.