here is a link to a site with online repair manuals that will explain how to do it. Look at the wiring diagrams, or have a shop do it.
http://bit.ly/mitchell_repair_manuals_online
http://repairpal.com/porsche-repair-in-san-diego-california
RepairPal Certified shops can diagnose and repair your 1997 Porsche Boxster. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.