@rechelon I've considered that sort of situation in different terms, "you're the only anarchist vs literally everyone else is a ruthless nazi", as well as the appropriate response in the opposite scenario, "there's exactly 1 nazi and everyone else is an anarchist". Both contrived and not really realistic scenarios to actually occur, but in the latter case it seems like you just shoot the nazi, easy enough, the risk of them existing at all seems greater than trying gentler means to change their worldview.
For the former, I mean "punch nazis" as a tactic kinda goes out the window when that's literally everyone else and will accomplish little but greatly risk your death. Leading me to the depressing conclusion that in such a scenario, that generally only things that are subtle and/or safe you should do, and more or less keep your head down and hope that eventually the tides shift to be more favorable just from the chaos that is humanity. Caching and archiving whatever you can so that if that fails to occur within your lifetime, maybe hundreds of years from now someone decent will discover it and make use of it.
That scenario and conclusion also has the presumption of uniformity and stability in the nazi society which I don't think could actually occur. If they've already genocided all the minorities they hate they'll just invent new ones, and I guess you'd have to try and work with them since due to their social position at least a few of them would shift towards less evil values.
I have no idea what the right approach would be in your hypothetical. It's bleaker than mine on account of being more feasible to actually occur and in the long term more stable, since two competing horrors can reinforce each other in a way that just one cannot.