Originally Posted by SgtB

You can just de-pin one side, shorten the wires, and then crimp new pins on and insert them back into the housings. It's tedious, but easy if you're patient.

I would just hack the wires in half in a dry hidden area and solder, and shrink wrap them. One big peice of glue impregnated shrink wrap over the entire splice group will seal it up.