Give them a long soak in a tub of freshwater and after drying off a shot of WD40 into the trigger mechanisms. The angular Spearfisherman company guns are single-piece trigger, so there is nothing to them. The Voit Swimaster guns have a two-piece trigger, the skinny barrel one is an Explorer, the other is a Magnum, but both are the same inside. While the screws will undo the pivot pins can seize in their respective mounting holes and it can be very hard to separate the clamshell handle halves. Rather than risk snapping the alloy castings it may be better to leave as is if they appear to be firmly stuck as the mechanism will still work.