Turn off and unplug the drill, or remove the battery
Open the chuck by turning it counterclockwise
Hold the drill firmly
Pull the drill bit straight out
If the bit is stuck, keep loosening the chuck until it releases
For keyless chucks, twist the chuck sleeve by hand
For keyed chucks, insert the chuck key and turn it counterclockwise
Remove the bit once the jaws are fully open
Tighten the chuck again if needed after removing the bit