drill won't lock

[crooner]

i have a bosch PSB700RES a 20mm bit got stuck in it the other day but i got it out , but i see now the button that locks the shaft won't work ,
chuck just keeps spinning ,i was going to replace the chuck but won't be able to get if off because it won't lock , is the drill capoot or can i do something to fix it

 

[foxhole]

put in vice and remove fixing screw , reverse the chuck off the spindle.

 

[crooner]

put in vice and remove fixing screw , reverse the chuck off the spindle.

managed to get the chuck off ,will order one today ,cheers

 

[crooner]

foxhole , i can't seem to find a chuck that looks like this one ,any idea where i can get a genuine bosch part