Hello - take a look at the link below to a DIY tech article on the door panel removal. I'm also attaching a link to our general section for tech articles on the 986. If you have any additional questions about the procedure, please feel free to post a Comment just below the article and one of our techs will get back to you with more details.
https://www.pelicanparts.com/techarticles/Boxster_Tech/76-BODY-Door_Panels/76-BODY-Door_Panels.htm
https://www.pelicanparts.com/boxster/boxster_tech.htm