start by unscrewing the bezel, you need a special tool for that, those 5 notches on the inside are for that tool, not sure where you get one for your particular light, but you can make one, get metal epoxy putty from any auto part store, activate it with your fingers, and when it get soft as clay push it into the glass and bezzel, so it takes that shape and fills notches, once it starts hardening remove it from your head, and let it harden fully. than use it to unscrew the bezzel. or you can use kitchen shrink wrap, put it over the head, and put putty on top of it, but you will have to make sure putty fills notches
or you can use wet\dry vac, remove the head, and from driver side suck the water out, and let it dry, thou it will most likely leave some residue on glass and reflector.
