I've done dozens of these.
I'd avoid a dremel if I were you. If you want to slip and screw up your finish, that's the tool. If you want electric power to grab your fret end and pull it out of the board, that's your tool.
Mask off the fret ends so that the area around them is taped over.. protect your finish. watch for scratching through, put on new tape.
fine file.. strokes running downward.. dont file in an upward motion pulling the fret out of the board at the end where it's MOST LIKELY to pull out.
You have to file them so they don't stick out.. and then you have to very slightly angle the fret end on top of the fret. not so much the string falls off when you fret.
then mask all around it. even on the board and use some emery paper or steel wool.. mask off pickups on elec.s so you don't get metal filings in the pups.
and smooth it out. again carefully. You can take more off.. but you can't put any on!
It's not hard, just be careful about pulling up on the fret end, scratching the finish on the neck, putting mars next to the fret on the board.. and get it nice and smooth when you're done.
don't be in a hurry.
TWANG
