How do you remove the Quill Feed Selector Handle?

I am talking about the knob you use to select quill feed speed. It has three positions, 6 at the top, 1.5 at left, and 3 at the bottom.
1969 Bridgeport Variable speed.

Mine is broken and needs to be replaced. ICAI has a quill feed speed handle at Twin-Grip Quill Feed Speed Handle , Acer, Alliant, ProtoTrak - Industrial Control & Automation, Inc
but it appears to be a quill feed handle, not for quill feed speed. I can make my own, but I don't see how the handle could be removed, and I know I will break it even more if I try to remove it.

Any help much appreciated.