Reply by bigblockyeti

Your chuck is almost certainly pressed onto a Jacobs taper, one of the best ways to get it off is to chuck up a router bit and try using the DP as an over arm router. I’ve fixed five that had the chuck come off while trying this. The spindle is one piece that fits into the quill. If you can drop the quill out by just removing the spring, you can then press the spindle from the quill, flip it and press the spindle from the chuck with a drift or something thin enough to fit through the hole in the bottom of the chuck.

-- "Lack of effort will result in failure with amazing predictability" - Me