Hey hughesra....FPB111 is absolutely correct. I've provided a link to one of our tech articles that'll help you do this. Please let us know how it goes and if you have anymore questions, feel free to post a Comment just below the article and someone will get back to you with some detailed tech info.
Best of luck!
Porsche 911 Carrera Headlamp Switch Replacement -
Pelican Technical Article - Porsche 996-997 - Porsche 911 Carrera Headlamp Switch Replacement
-Dmitry