Not so easy. How do the people (everywhere) then exchange their Fed Notes for real money?
They are doing it smart, cutting off the slush funds, seizing assets, seizing bank accounts. Use their bullshit paper to pay off the debts, THEN end the Fed and issue real money.
I'm not sure you are clear on what a rogue nuclear nation is.
If the Obama presidency is ruled to be illegal, then technically the actions (including debts) of that government during that time would be invalid. How many trillions worth of debt can then be dissolved? If the assets seized can then pay off the remaining debt, then that is a viable strategy.