[central_va]

All you need is the legislatures of 3/4s of the states to agree to dissolve the United States and it's done.

Are you talking Constitutional Convention?

[Bubba Ho-Tep]

Yes. Get two thirds of the states to demand it. Write an amendment that says something like “All the above is null and void and the states are all on their own to do what they want.” Get 38 state legislatures to pass it.