Well on the 16 you first remove the lower window outside molding which has ONE screw at the edge of the door. Then its just carefully pry it out. I would do that with the window down. Then roll up the window and remove the inside door panel. Unplug keypad connector. To remove keypad, pry the keypad off (it is held on with double sided tape). Clean off all the old tape and clean surface thoroughly.
Then attach new keypad and install in reverse procedure.