This is not the first chuck I've replaced, but last time there was a
spindle lock which made life easier. The screw is out but I'm having
no joy with smacking the allan wrench, but I haven't gone to the
bigger hammer yet.
On this older milwaukee drill there is a hex portion of the shaft
below the chuck. I can't tell whether this is part of the chuck and
should come off, or is it part of the shaft and I could put a wrench
on it to lock the spindle. I can't read the model number, the closest
manual I could find on the milwaukee site just gave the typical
instructions with no mention of the hex section. It looks like if
that weren't there the new chuck would end up too close to the body of
the drill, so I kinda suspect it doesn't come off.