1. Park the car on a flat surface and apply the parking brake.
2. Locate the access cap on the door panel, usually near the door handle. Pry it off using a flat-head screwdriver or trim removal tool.
3. Remove the screws under the access cap using a Phillips-head screwdriver.
4. Gently pry the door panel away from the door, starting from the bottom and working your way up. Be mindful of the electrical connectors and clips holding the panel in place.
5. Disconnect the electrical connectors by pressing the release tabs and unplugging them.
6. Locate the three bolts that hold the door mirror in place, usually located on the back of the mirror housing.
7. Use a socket wrench to loosen and remove the bolts.
8. Carefully pull the door mirror out of its socket, taking care not to drop it.
9. Disconnect the electrical connector from the door mirror by pressing the release tab and unplugging it.
10. Install the new door mirror by aligning it with the socket and inserting the three bolts.
11. Tighten the bolts using a socket wrench.
12. Reconnect the electrical connector to the door mirror.
13. Reattach the door panel by aligning it with the door frame and inserting the screws.
14. Replace the access cap on the door panel.
Note: If your specific Mercedes E320 model has different steps, refer to your vehicle's owner's manual or a reliable online resource for guidance.
