First I would try clamping the driver in a vise. With the driver clamped in the vise you can attempt to pull the bit out of the chuck.
If the driver bit won't slide out then you will need to cut the chuck off of the drill. Depending on how deeply the driver was inserted into the drill you may be able to cut perpendicular to the drill itself. Just be careful to not cut the end off of the drill's spindle.
Once the bit has been removed then you can use the regular methods to remove the chuck. We have a very informative article and video available that will provide you with all of the information you will need to remove the chuck. The following link will lead you to the article...
When I have the drill on speed 2 and after I let the trigger go you can hear the gears grind when it stops. What would I need to do to correct problem?