Put gloves on your hands. Hold the hand electric drill tightly with one hand, and hold the gourd mouth of the hand electric drill with the other hand, and rotate it hard to expose the hole where the electric drill is installed.
If there is a circle of teeth at the front end of the hand drill, twist it with a special key. Take out the drill bit to be installed, put it on the hole exposed at the front end of the hand electric drill, and rotate it clockwise by hand to clamp the drill bit.
Adjust the depth position of the drill bit into the hole and lock it clockwise with a special key.
Plug in the power cord plug of the electric hand drill, idle for two seconds, and observe whether the drill bit of the electric hand drill is firmly installed.