1. Align the sector knob with the cork, and tighten it vertically and forcefully, being careful not to tilt it until the metal screw can be seen in the center of the lower end of the cork.

2. Slowly and forcefully twist the plastic cover at the lower end of the fan, and the cork will gradually rise from the bottleneck together with the plastic screw cover and exit the bottleneck.

Please note: you can't give up the second step and pull it out too hard, so it is difficult for people or women with small strength to pull it out; A strong person may just pull the wire out of the cork, and the cork won't move, just like a slippery wire, and it won't work so well if you screw it in.