On and Off switch corroded

On and Off switch corroded

After many trips to the beach and I KNOW sunscreen/sand/sweat etc, my on/ off switch became really hard to work. I would have to press it really hard, or at a certain angle to get the camera to power on. Once on, the camera worked perfectly. Finally came the day where I could not power the camera on anymore. I know the switch or button either needs cleaned or replaced. Maybe the electric contacts have become corroded. Any idea on how to do this?