You will need to loosen the pilar that houses the tweater. There is a screw behind the airback label. Unscrew that, then loosen the visor screws and you may also need to loosen the overhead consol screws. Gently pull the headliner down and feel for the wire from the existing visor that plugs into the harness in the headliner.
It is a bitch and glued down pretty well. Pull it loose, unhook the plug and plug the new one in. It is pretty simple...be gentle though.:thumbsup: