This eccentric bushing:
belongs to the hand crank of this machine:
It cannot be seen clearly in the photo, but the small blocking bar inside the bushing is not hovering over but rather, is sunk into a notch in the same surface which contains the thread.
I would like to disassemble the bushing, because the crank is badly aligned. How can I do this? Should I remove the small blocking bar inside in order to disassemble? Do I need a special tool?