Seat latch and heater control "knob" removal

I'm trying to remove the "knobs" from my Heater-a/c controls and also from the seat latch mechanism on my 73 A-body? Do you just pull until they come off, or is there some trick I don't see?
Once you get them off, do you just shove them on to reattach, or use some sort of adhesive?

Seems like a dumb question, but I've tried pulling them off without luck.

Thanks

there is usually a small hex set screw that threads in from the bottom of the knob.

I believe the '73 and up A-bodies have a press on plastic knob.