Removing Heater Control knobs?

[custom10nut]

Please tell me that there’s a safe way to separate the knob from the lever on my heater control.
I finally got around to changing out my old control unit, with another unit that I picked up at a Swap Meet.
I was careful with removal disassembly/reassembly and reinstall.
The first time I moved the levers, the middle knob for the fan control broke off in my fingers.
I figured out hot to disassemble the old one without breaking anything, but don’t want to break the knobs off to get the lever out of face.
Are there any solutions to this or did I just waste my money and Ave to buy another one?