The correct term is nock, a brass nock. You can probably remove it with any needle nose pliers etc. Just becareful not to damage the string or loop. They are hard but will unbend at the seam.
I hate removing the brass nock. I messed my my serving once doing it. It was mono serving, since then I use string serving. They sell a nock set pliers that has a little gizmo to remove without damaging. But I still pull apart with needle nose.
Yup, monofiliment serving is the worst idea in archery ever. LOL, here's your nock pliers, they are the best for this purpose, I have a set and am thankful for them every time I need them.
remove brass anchor on string.
