I recently replaced the driver's side mirror on my 94 E320.
I used the procedure below.

1. Go to Ebay and find used E320 mirror, any color.
2.Buy mirror. Mine cost $25.00
3. Remove small cover on inside of door to expose three philips screws.
4. Use screwdriver to remove screws. Screws turn counter-clockwise.
5.Disconnect plastic plug coming from mirror motor control.
6. If new (used) mirror is different color than old, swap the plastic trim. (It pops off)
7. Reassambly is reversal of removal.

Good luck.