If damage occurs to the outside mirror on your Mazda Miata, you can remove the entire unit and replace it with a new one with relative ease. The mirror attaches to the outside of the body with two bolts hidden inside the mirror base. The mirrors on the Miata are heated and adjusted electrically from inside the car and require you to remove the door panels to access the electrical connections before you can remove the assembly. You can buy a new mirror assembly from the Mazda dealer or a used one from many salvage yards.
Open the door of your Miata and locate the three screws in the door panel. The first is located in the trim plate where the door handle is. A second lies below that inside the grab handle on the door. The last one is found in the upper end of the door handle.
Remove the three retaining screws on the door with a Phillips screwdriver. Locate the three push in retainers on the panel. There is one on the face of the panel near the upper front corner and two in the rear door jam.
Lift the centre of the retainers with a flat tool or small screwdriver. Pull the door panel out from the bottom. Lift the panel out of the window track and move it out far enough to access the wiring behind it.
Remove the electrical connectors for the window and door locks by unplugging them from the switches. Unplug the wires from the door speakers and remove the panel. Set it aside.
Locate the wiring connector for the mirror heater and adjustment motor. Unplug it from the wiring harness connector on the inside of the door.
Turn the mirror on your Miata sideways to reveal the two mounting bolts inside the base. Remove the bolts with a socket and ratchet. Pull the mirror off the body, fishing the wires out of the hole in the body.