1. Find the position of the two hexagon socket screws at the diagonal beam under the bicycle beam. This is where the bottle cage is installed. First use a tool to unscrew these two screws.
2. Unpack the bottle cage, then put the bottle cage on the installation position and check whether the screw holes are right.
3. Hold the bottle cage with one hand, pick up the screw with the other hand, and put it into the hole, and turn the screw with your hand to lock the screw slowly. Tighten both screws first to fix the bottle cage first.
4. Use the hex wrench of the same model to tighten the two screws firmly. Break the bottle cage with your hand to see if it shakes. If it is loose, continue to lock it.
5. Choose a water bottle of the right size, and then put it on the bottle cage for a try. Generally, water bottles of the same size are available.