First lossen the string untill theres a lot of slcak, then use a wire cutter to cut the wires in the middle. If you dont have a cutter, then youll have to keep loosening untill they come off or you can unwind them by hand. Then take the string and push it through the bridge. They come right out of the back of the bridge. To string, just take the tip of the string and slide it through the bridge. Also make sure the string stays on the notch when tightening.