Cordless drill - remove chuck

[opps]

A friend has a Worx cordless drill, she says that drill bits fall out of the chuck. I told her that she can get a replacement chuck. I was expecting it to be held in place by an allen key bolt. On closer inspection it looks like a "phillips" type screwhead but I can not turn it in either direction. The pistol part of the body actually starts to flex/bend when I try to remove the bolt.

Is it possible that it is not a bolt?

 

[big-all]

some cheaper drills used to have locking rings on the inner end off the chuck that you can twist or slide into the lock position not the numbered clutch but on the chuck its self

 

[opps]

some cheaper drills used to have locking rings on the inner end off the chuck that you can twist or slide into the lock position not the numbered clutch but on the chuck its self

Thanks. Will check that out.