Use a pair of Vise-Grip pliers on the key-less chuck and Channel-lock pliers on the stuck bit. Holding the drill with the drill facing away from you (as in use), turn the chuck clockwise and the bit counterclockwise.
A Phillips screwdriver, or a nail can be inserted into one of the holes for the chuck key, and then use a "pipe" wrench on the collar to break it loose. Once loose, you can then turn it enough to release the drill bit.
I once saw instructions on a package of a new chuck. Lock the drill in a vice, open the chuck. It should have an Allen screw inside, behind the teeth of the chuck. Find the right wrench and tap with a hammer. I can't remember which way to tap. Some items like that have reverse thread. If you have t handle allens, it will probably be easier, may be able to do it by hand. I haven't tried it, don't know how easy it is. Good luck.
Use a key chuck. If the drill is chuckless, then just use your hands.
If the drill is not "chuckless" you will have to find a chuck key that will fit your brand of drill, insert and turn counterclockwise to release the bit.
Some are screwed on with reverse thread and some are a 'Morse taper' fit. You have to determine which. The 'Morse taper' fit is knocked off with a sharp blow from a 'dead blow' hammer.
You turn the outer ring clockwise while holding the inner ring.
Normally with a chuck key.
If you have the drill in your hand with the chuck away from you, if the rotation goes clockwise it is going forward and if it is counterclockwise it is going in reverse. When you use the drill you usually go forward. To remove the drill bit look for the reverse lever and once it is going counterclockwise place your hand on the front part of the chuck and the drill bit should be released.
You press the holding ring toward the body of the drill and slightly twist and pull the bit away from the chuck.
Tighten the drill bit in the chuck.
It's the part of the drill that holds the drill bit.
chuck
A 'chuck key ' is used, there are 2-3 sizes.
a jt3 chuck is a chuck for a drill that takes a jt3 tapered arbour for fitting into lathes or pillar bench drills
The drill chuck
"chuck"
A three jaw chuck is usual.
Chuck