Don't force it by hand—you can get cut. First, make sure the chuck is fully opened. If the drill bit still won't release, here's what to do.
- Grip the tool firmly. Open the chuck jaws as wide as they go.
- If the bit is still lodged, use a pair of pliers to grip the shank of the drill bit firmly.
- Gently pull the bit straight out while holding the chuck steady. Pulling it out by hand may cause injury from the sharp edge, so the pliers are the safe way.
If that didn't work, the bit might be bent or the chuck damaged. Inspect for debris in the chuck jaws. Clean them out.
For future use, avoid pressing excessively on the tool during drilling. That can jam bits and damage the chuck mechanism.