A:Answer Yep, take the port door off. It's no longer water proof in any way but if you want to use a Mic that shouldn't matter. Keep in mind, the Gopro Mic adapter is a terrible product. Just look at the reviews and complaints. I did and bought one anyway, knowing what I was getting into, and because there is no option yet. There is a constant clicking noise in my audio when I use it depending on the position of the cord and plug going into the port. If I'm careful I can eliminate it by pressing the plug in while recording. Good luck!