Here's a copy of something I've posted many times. If your lfs sold you these demonic fish as "cycle starters"; I'd politely tell them they're nuts and have them remove them.
This may have been me, I always suggest this; but most people think its
silly...until they try it. Tiny hook (hair hook, used to catch bait. Flatten the
barb and bait with a bit of raw shrimp..after the little monster has been eating
it for a day or two. A lfs called me several times, when I I lived in another
state, to help them get unwanted fish out of customer's tanks (almost always
damsels). I never failed, nor hurt a fish (much). I think this one of the most
common questions on this forum. I suspect it is often the result of lfs selling
damsels as "cycle starters".. I'll bet I've posted this reply 20 times; I'm
going to copy & save it...I type very slowly. BTW, I never heard from anyone
that tried this and failed, but have heard several success stories. IMO, it is
no big deal on the fish, far less stressful ,(on the damsel AND tankmates),than chasing them around for hours or dismantling the tank.