1.Remove the 3-jaw chuck by rotating this six parts with a wrench;
2.Install this part in the designated position of the 4-jaw chuck and
ensure that the scale line in the right position;
3.Install the locking screw and ensure that the locking screw is in the locating slot;
4.Rotate the part and ensure that the semicircular groove coincides with the chuck installation hole;
5.Rotate the six parts with a wrench to lock the chuck