The states should call a Constitutional Convention to allow states to leave and /or to dissolve the US and/or dissolve the current Federal government and let the state reform as the chose
I believe the Fed would have not legal power to stop Secession if the states approve it under terms of a Constitutional Convention
In fact the simple threat of a Constitutional Convention that may dissolve the Fed government may be enough
our current crop would use this to radically seize power and remove government power restrictions altogether.
The last ConCon we had completely tossed the Articles of Confederation in favor of our current Constitution. I do not have any faith that 3/4 of the states' representatives have OUR unalienable rights as concern. The Bill of Rights would be first to perish.
I could see the "2nd Bill of Rights" getting passed and you and I having a "right to a job," a "right to a dwelling," a "right to food," and a "right to education," which sounds well and good to an idiot.....
until the realization is "education" = forced indoctrination of Dear Reader's most famous speeches, "dwelling" = soviet style apartments with communal kitchens and bathrooms, "food" = gruel, and "job" = make work programs like the WPA.