I hope anybody here can help me with my Sirocco rim break rear wheel.
I simply cannot remove the end cap for the QR skewer from the axle. (The part circled in red in the image).

I believe this end cap is screwed into the axle but when I try to unscrew this by holding the nut on the other end of the axle at the freehub with a spanner, then I am tightening the left handed threaded nut holding the freehub more and more and I am getting afraid that the thread might become damaged.

Somewhere I read that there should be 2 flats on the axle on non drive side just behind the black nut in question and before the small lock ring but I don't seem to have them on my wheel / axle and I don't think they would be of much help considering the amount of force I have already applied to the nut to get it off.
Of course I also assume that this is a normal RH thread.

I need to get the axle out to replace my bearings.
Thanks to al for reading and helping
Robert