No wait, my problem isn't resolved. The reason I wanted to remove the shiftknob was to re-attach the shiftboot to the shiftknob. To do that I need to screw even more the shiftknob till it reach the shiftboot.
How the hell do I do that, I tried screwing it as hard as I can but I came to a point where it wont move anymore. Could the shiftboot have been glued to the knob originaly?