If it's like the W210 the mechanism just pops out. Look for a small oblong cutout at the top back edge of the mechanism. Insert a couple of finger tips and pull up smartly. When replacing look for 'hooks' then catch them and push down. The mechanism is designed to work without any lubricant. You might try soaking in warm soapy water to remove any debris.

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Good luck.






1998 E320 Wagon