Chosen Solution
I have search how to unscrew different types of nuts but I cannot get a hit on this type. Seems to have some notches like pin nuts on cars but pin wrenches will be too big for this. Is there a right tool or method? Thanks!
@teaouu yes there is. What you need to use is a bit, or screwdriver for the safety screws. Something like this
will work. Now you can make your own by using a common flat tip screwdriver and cut a notch into the center of it (grinding wheel works best for that ;-).
