I had to do it^^
I had a Nightmare before CHristmas bag that was falling to pices. On every zipper it had Jack Skellington"s face, so I salvaged them and made a beautiful and unique belly ring!
This is so simple, it's child's play: open the jump ring with plires and slip the pendant into the ring. Slip the ring with the pendant on it through the tiny hole at the bottom of the belly ring. Close the jump ring very tightly!