Joystick knob, how to unscrew?

Hi,

I’m trying to assemble the picade, but I can’t remove the joystick knob. In the video it does not seem to be fastened very hard. Can I apply a screw driver to the bottom of the joystick shaft on the bottom of the joystick? Or is thare any other good trick?

Screwdriver applied to the bottom of the shaft is the correct method!

(Back after a trip to the country side). I tried with a screwdriver, but to no use. I even tried twisting the wrong way. Just to be sure, there is no pushing or pulling required to unscrew the knob?