Thanks, everyone, for the really good ideas on loosening the chuck and faceplate. @Brian Gustin chucking up a lever arm brought a "Doh!" -- what a simple idea, embarrassed I didn't think of it. @Kent Reisdorph I've got a Talon; the adapter has two threaded holes for, I imagine, set screws, but I don't believe those were included. I'll re-check the packaging. @Dave Landers I like the idea of drilling a hole in the faceplate, then keeping an eye out for one of @Marc Banka's pin spanner.