That still doesn't tell me how to safely print with a hardcore printer, including with different nozzle sizes.
We cleaned the stock ones by unscrewing them, hitting them with a blow torch, and then screwing them back in. I don't think we screwed it all the way back in, because material has oozed out up in there, which we have struggled to remove, especially since we can't get it unscrewed again. I think I just need some better wrenches.