Just like the clutch master, when changing the central shaft, the locking screw of the crank is twisted. There is no other way, so we can only remove one side of the toothed plate, then remove the locking screw of the central shaft in the five-way position, hold the central shaft in the five-way position on one side of the toothed plate with a wooden stick, and hold the central shaft in the other side with the ejector pin of the crank disassembly tool, and knock it hard. It should be noted that in the case that there is no wooden stick on the side of the dental disc, the actual force on how to beat the central shaft is not great. Pull out the top of the stick and it will be done in a few times.