I would like to exchange the JoWo nib unit on my ASA Nauka with another different JoWo nib unit (of the same size), but I have been neither able to unscrew it from the pen section nor pull out the nib & feed from it.
Please, does anyone know whether it's possible or not?
And, if possible, how should I do it?
I understand that JoWo units are screwed on the pen section, so I have tried to unscrew it... but I have exerted quite a force without it moving any millimetre! It seems to be glued or "fused" to the section...