Anarchism won't just happen. It will only succeed when the majority of society have the ability and the wish to run it in their own interests. In practice we see revolution as building from the ground up. Workers infringing more and more on the bosses' profit margins and eventually questioning their right to make a profit on the backs of the working class and taking over their workplace. As the struggle progresses more workers setup workplace commitees, councils and eventually defence militias.
Groups begin to federate upwards on the basis of democracy, delegation and recallability.
Inevitably when faced with a major challenge the bosses and state will be ready to fight to defend their wealth and power. We have to be ready to fight to defend and forward the revolution. With good organisation, most people on our side and much of the army coming over we would hope this would not be a long or bloody fight. We are certain the system can't be reformed out of existence. It has to be destroyed.