Top of door panel on inside of mirror is a triangle looking piece. Remove that piece, has fasteners that will unclip, pull top first then lift up. Now you have exposed the mounting fasteners to remove the mirror. According to MITCHELL
Remove the interior panel with a phillips head screwdriver. Disconnect the plastic tabs from the door and pull the panel off by pulling toward you. Roll the window up. Use a screwdriver to pry all plastic tabs off and put door panel off to the side. Remove wire harness from passenger mirror. Remove both bolts that fasten mirror to door. Mirror will now come off. Install new mirror with reverse procedure.