Depends on the nature of the disagreement and the reasonability of the other side. Preferred solutions are, in decreasing order of preference:

• Come to an agreement through compromise and debate
• Proactively demonstrate why the other side is wrong by doing the thing and showing them why it works
• Agree to disagree (i.e. tolerance of diversity)
• Tell the other party to fuck off (i.e. freedom of dissociation)
• Worst case scenario, the minimum defensive violence necessary to protect ourselves

We're at the bottom bullet point with respect to capitalists. We've been at the bottom point since capitalism was established, because it was established through violence and has been a continuous source of violence against humanity. But for most other problems, the other possibilities are better alternatives.

When push comes to shove we're just gonna have to play it by ear, as has always been the case, but anarchism provides a framework to rule out certain possibilities because they do not reflect the future we desire (i.e. prisons, police, states, standing armies, etc.) and therefore are ineffective methods for bringing about a liberatory future.