Odds are, you've seen someone with captive bead ring body jewelry and wondered exactly how it was put on and taken off. If you're new to piercings, or don't have piercings that require CBR, it can be a bit puzzling—the name isn't a lie, the bead is "captive." This can lead to issues when you're trying to figure out how to change your own jewelry, because odds are most people will just tell you to go see your piercer. If you're in a situation where a trip to the piercer isn't possible, that's going to be a frustrating answer.
Admittedly, these people are giving you good advice: if you do this wrong, you could get an infection or tear your skin. Most piercers will do it for you for free, just a quick trip to the studio and you're in and out with no charge. But a trip to the piercing studio isn't always in the cards, particularly for something as simple as a jewelry change. It's important to know what you're doing so you don't end up hurting yourself. Regardless, if the piercing is infected or not yet healed, don't do this outside of a piercing studio.
If you intend for this to be a regular thing, it's a good idea to invest in a pair of ring opening pliers and a pair of ring closing pliers. They're exactly what they sound like. If you don't have a pair of ring opening pliers, a pair of needle-nosed pliers will do the trick. Beware, though, because this is where people mess up. Needle-nosed pliers are not made for body jewelry. They can scratch the metal of the CBR, making it susceptible to bacterial infection. You need to make sure you don't scratch the surface of your ring, and you do that by wrapping the needle-nose with some kind of soft tape such as electrical or masking.
Make sure the tape is clean, but know that this still isn't quite sterile as visiting your piercer would be.
Now, place the wrapped needle-nosed end into the center of the CBR and slowly pry the ring open. Hold your other hand under the ring to catch the bead when it falls out. Once it does, there will be a little space in the ring. If the gap doesn't look large enough to remove the piercing, pry it open a little more with your pliers, but be careful not to warp the shape of the metal. Eventually, once you have enough space, the ring will reach a point where it can be turned and then carefully pulled away from the skin.
If the space still isn't big enough, turn it back, open it more, and try again. Never force it out.
To put a captive bead ring in, first make sure both the jewelry and your hands are clean. If you bought the jewelry from a piercing studio and kept it in its package, it should be fine. Open the new CBR using the same method you did the last one. Place the ball somewhere clean that it will not roll away (a tray is preferred) while you insert the ring. Carefully touch one end of the ring to the piercing hole and rotate the ring, being careful to allow it to slide through the piercing. This may take some practice and gentle prodding.
Again, don't force it. If you feel it catch or think it's not going in the right direction, remove the ring and try again. Generally, the less you think about it, the easier it is.
Use your pliers to gently close the ring, leaving just enough room to allow the bead to snap in place. The bead will either have a hole all the way through or indentations on both sides, which is where the ring holds the bead. Grab the bead, line up the indentations up with the ends of the jewelry, and firmly push to pop the bead between them. If the bead is correctly inserted, you shouldn't be able to pull it back out, but it should still rotate on the axis of the ring itself.
If you ordered your jewelry from an online store and don't know if it has been autoclaved, it's imperative that you take it to a local piercing studio and ask them to autoclave it for you. There will probably be a small charge, and it will probably take overnight—you might as well ask them to change your piercing when you pick it up.