How do I remove a 4' Eunicid worm?

[mysterybox]

I have a 48 inch 55 gallon stony reef tank, and I've noticed that I had an Eunicid worm for sometime now. It's at least 4 feet long. I wasn't too worried at first, but lately my fish are all huddled up on the left front of my tank at night where only my clowns "slept". One of my chromis looks likes it's been in a fight. Tonight I noticed the worm (located deep inside a bottom rock on the right side) slithering all the way toward the left side (behind & underneath the rock of course!) where my fish are. I can't take the rocks apart due to a clam, & stony corals that are on the rocks above. Do you have any suggestions on how I can catch, kill, eliminate this creature?