Bit stuck in Bosch PS20 keyless chuck

Can not see what model you have. Is it a keyless chuck or an SDS chuck? With a keyless chuck hold the machine in a vice by the drill bit. now tap the chuck with a hammer or pin punch & hammer. DONOT hit the chuck on the jaws gut on the rim around them. I have had success using this method. If it is an SDS type chuck pull the chuck cap up as far as possible along the bit them if there are any ring springs you will have to try remove them then slide the sleeve up the bit, now you should be able to remove any steel balls. If the bit does not come out now hold bit in vice as before and tap on tool holder.

Try holding the bit in a vice and gently tap the chuck off of the bit and see it it releases the pressure on the jaws.

Keyless Chucks
Open chuck jaws by turning plastic collar with fingers and insert shank of bit about 3/4" into
chuck. Tighten plastic collar CLOCKWISE while depressing spindle lock button (F) on the right
side of the tool housing (Fig. 4). To release bit, turn plastic collar COUNTERCLOCKWISE while
depressing the spindle lock button (Fig. 4).
NOTE: DO NOT DEPRESS LOCK BUTTON WHILE OPERATING DRILL or while the chuck is
moving.

Link to manual:- http://servicenet.dewalt.com/Products/Detail?isId=true&productNumber=DW222&selectedType=2752#

what you can try is to spray penetrating fluid on the chuck collar, jaws. Next if you have a GOOD pair of gloves hold the collar and then using the drill motor try and loosen the chuck. If you have a vise with a pair of soft jaws without clamping too tight you can try the same thing. The main purpose is to let the drill torque loosen the chuck collar to release the bit.

For the pictured drill motor, you put the bit in and use a "chuck key" to tighten the chuck onto the bit...

If the photo is not your machine but you have an SDS type chuck, you insert the bit, pull back on a collar and twist the bit until you feel it engage and release the collar. When seated properly you cannot pull the bit out without pulling back on the collar.

pull the collar on the front forward and insert hex end of bit in and let collar go back. this locks the bit in.

This drill has a keyless chuck. Put your bit in the chuck and hold the collar of the chuck while pressing the trigger in the forward position. To undo the chuck do this in reverse. You can also hand tighten the keyless chuck if you prefer. I have a 1/4' adapter that I keep in my drill so I can change bits quickly.

it depends what chuck (the part the drill bit goes into) on the old ones you had a chuck key that slots into the hole on the side and connects to the teeth to tighten the chuck around the bit, keyless chucks are tightened by hand instead of the key and the SDS have a collar that pulls down, you have to turn the bit so it then slots in then just release the collar to fix it in place good luck!!!

without having the exact model number for this tool I have in the past removed the outer collar on the quick release holder. After that you take out the small steel ball and the bit would come out but If you can provide the model I will look at it and see and call a friend that is a Bosch Authorized Service and see what they do in this case.

Have you pulled the collar to release the pressure on the steel balls. Just pull the collar usually forward and slide on the shaft and then release and twist till it locks. Let me know if I can help further