If you're the owner of a crossbow, at some point you'll need to get the bowstring replaced. This process is known as restringing a crossbow. Crossbow strings will eventually wear out and need to be replaced - typically every 1-3 years depending on how often the bow is used. Restringing a crossbow is not a difficult task, but it's important to do it correctly to avoid damaging the bow. The cost of having a crossbow restrung will vary depending on where you take it and who does the work. Expect to pay anywhere from $30-$100 for professional string replacement service. You can also buy replacement crossbow strings online or at your local sporting goods store for around $20-$60. If you're handy with tools, you can replace the string yourself following these steps:
1) Remove the old string: First, unstring the crossbow by unscrewing the limb bolts and removing the limbs from the stock. Next, remove any serving (protective covering) from around the ends of the old string using a razor blade or sharp knife. Be careful not to cut into the underlying bowstring material. Finally, pull out both ends of the old string through their respective nocks (the plastic or metal cups at each end of the string).
2) Install new string: Start by threading one end of the new string through its nock and then tie an overhand knot in that end to secure it in place. Next, feed approximately 10 inches of slack into each limb tip before looping one end of the string back towards itself and tying another overhand knot (this second knot should be about 3 inches away from first knot). Now pull on both ends of slack until all excess slack has been removed - this will help keep your new string tight and reduce noise when shooting. Finally, reattach both limbs to your crossbow stock and screw down tightly before giving your new string a few practice shots.