The driver's side and passenger's side view mirrors attach to your 2002 Honda Civic with bolts that mount to the mirror shell, extend completely through the door and secure from the inside. Replacing the side mirror on your '02 Honda Civic does not require that you dismantle the door, because an access panel is located on the inner door panel that allows you to access the wiring harness for the mirror and mounting nuts.
Remove the access panel from the inner panel of the door by pulling it off with your hands. The panel has small tabs on the back that fit into slots in the inner door panel. By pulling on the cover, you pull the tabs out of the slots. The access panel is across from the side view mirror.
Pull the wiring harness out of the sub frame of the door, located behind the access panel. The harness consists of two plastic connectors. Pull the two connectors apart.
Remove the three nuts that secure the mirror to the door using a socket and ratchet. Hold the mirror while you remove the final nut to prevent the mirror from falling to the ground.
Pull the mirror away from the Civic's door and then slide the studs on the new mirror through the door.
Secure the mirror to the door by threading the nuts onto the bolts with your fingers and then tighten the nuts with the socket.
Push the two connectors of the wiring harness together and then tuck the harness back into the sub frame of the door.
Place the access panel back onto the inner panel of the door, line up the tabs with the holes on the inner panel and then push the access panel into place.