When the fan is removed from the heat sink, you can see that there is a label paper in the center of the fan blade with the parameters of the fan printed on it. Carefully remove the label and be careful not to deform it. At this time, you can see a small hole in the middle, and there is a clasp in the hole. After the snap ring is removed, the fan blade can be removed. Clean the fan shaft after disassembly, and do not lose the plastic gasket on the fan shaft. After the shaft sleeve in the stator is screwed and wiped clean, it can be oiled. It is better to use sewing machine oil and four-stroke engine oil in winter. It is best to use the refrigerator to freeze oil. You can separate the shaft from the sleeve. Don't put too much oil on it. After assembling the clasp, drop a drop of oil and stick the label on it.