1978 CB550k rocker arm shaft removal problem

I have a 1978 CB550k that has the retaining plugs on the rocker arm shafts that need to be removed before taking out the actual shafts. I've searched on the forum and tried all suggestions; threading the nut Hal way off the retaining pins and tapping on a socket to push them out etc. but they refuse to move, all four of them.

If anyone has any suggestions as to how I might get these retainers out you would make my day!

Thanks