Locate the access panel on the vehicle's inside door panel which is near the A pillar, if there are no screws you just have to pry it off with a screw driver.
Disconnect the wiring harness that extends from the motor that's inside the housing. This requires that you pull up on the plastic connector that plugs into the mirror switch on the access panel.
Remove the three nuts that secure the mirror housing's bolts to the door and pull the housing away from the door.
Slide the studs of the new mirror housing through the door and secure it with the nuts.
Check operation to see if it is working...