I went to the store.

They guy had the chuck removed in a bout 2 minutes.

Thew trick was not in using the chuck key.

What he did was use the short end of a large diameter
allen wrench in the mouth of the chuck and tighten it down.

Then a tap with a hammer got it loose.

No vise needed, no sweat. Maybe this is in the
instruction manual with new drills. I didn't have
the book.

:-/