Unplug the drill or remove the battery
Set the drill to reverse if needed
Open the chuck by turning it counterclockwise
Hold the chuck firmly
Pull the drill bit straight out
If the bit is stuck, use the chuck key if your drill has one
Tighten and loosen the chuck a few times to free the bit
Apply penetrating oil if the bit is jammed
Use pliers to grip the bit if it is exposed enough
Replace the bit and tighten the chuck securely if needed