Sealtronics will make sure that neither you nor water get in there
again. Prep the area first by buffing with sandpaper and acetone. The
acetone wipe should be very brief (1/2 a second MAX) or you'll start
making a horrible mess.

You can put dye in the mix to improve the appearance. Casting Craft is a
good brand and it comes in an assortment of colours.

Sealtronics, as the name implies, seals the electronics. You won't have
to remove anything.