Mike,
You'll nevercatch a bristleworm with tweezers. I generally never counsel anyone to remove a bristleworm, as they are such helpful residents in a reef system, and are frequently the victims of bad press, convicted of killing something that was already dead when found, or were simply cleaning away dead tissue.
If you're absolutely certain you saw the worm munching down on live, perfectly healthy polyps, then it may be one of the rare troublemakers. Please be sure.
Traps are available commercially - you don't want to touch these guys! Or you can make your own by cutting off the top of a plastic coke bottle, and glueing it back in place w/silicone cement, but reversed - opening inside the bottle. Bait it, place near where you think its hole is, and leave it overnight. If you have shrimp, they may get to it first. Another trap is to wrap bait in a piece of old nylon stocking. Their legs will get caught in the material and can then be removed w/tweezers or tongs.
Please do make sure you've got him dead to rights before taking action.
regards,
rw