Opting out is an individual choice. You don’t have to form unions or demonstrations. You don’t need to convince anyone or get violent in the process. You just say no to credit for starters. If you feel evil, you can save your money and join the owner side, which I have done. You can also work to become completely independent of the system which I would like to (this is harder than simply buying into the financial system as it currently exists because you need to make your own system to replace it—this usually takes the form of a self-sufficient homestead.)
This is from Jacob Lund-Fisker’s excellent wide-angle take on the present wage slavery situation.
Warning: contains actual stuff about how banking and usury work.