fancy pliers are the best way

I use to do this: take a butter knife and use the not "sharp" side and work it into the opening in the brass nock and twist it. This will take several tries, once it starts moving apart it gets easier. Get it open enough to take it off.

You could also grab both sides of the opening using two sets of needle nose pliers and try to pull them apart.

Worked for me, until I got those fancy pliers that is, now it takes me about 2 seconds to get a nock off the string. [8D]

--Bob