Tutorial - Open and Close Jump Rings
1. Grip the jump ring on each side of the opening using two sets of flat-nosed pliers. If you don't have two sets of pliers then grip with one set of pliers (in your dominant hand) and thumb and forefinger of your non-dominant hand instead.
2. To open the jump ring, still gripping, bring one set of pliers towards you, opening the jump ring like a door rather than pulling it apart.
3. Slide your component onto the ring, then reverse the action of your pliers to bring the ends neatly back together.