Drills with electrical cords use a key chuck system in which the drill bit is loosened and tightened by using a key inserted into the chuck of the drill. With cordless drills there is no need for a key because the drill bit is added and removed using the power of the drill for loosening and tightening.
How to Change a Drill Bit on a Cordless Drill
Check that the battery is charged in the drill. Do this by pressing the trigger of the drill. If there is power, you can change the drill bit.
Switch the drill to reverse mode. Firmly grasp the handle of the drill and press the trigger while holding the chuck between your index finger and thumb of your other hand. This powers the drill and opens the jaws of the chuck.
Release the trigger. If there is a drill bit in the chuck, you can pull the bit from the chuck.
Switch the drill to forward mode. Insert the smooth end of the drill bit into the mouth of the chuck.
Hold the drill bit between your index finger and middle finger. Hold the chuck between your thumb and last two fingers.
Press the trigger of the drill. The jaws of the chuck will close around the drill bit. Keep the drill bit parallel to the drill; your index and middle finger should provide sufficient support for this.
Release the trigger of the drill when you feel the chuck turning between in your hand. The new drill bit is now ready for use.