It would take an act of Congress to amend the Constitution

Although rare, it has happened before

Need one amendment repealing the sketchy 16th...plus another, simultaneous amendment specifically forbidding Congress to ever create an income tax and specifically forbidding all forms of federal taxation except [insert accurate wording here - tariffs, etc.]

I used to say replace with 1% federal sales tax, but the vampires would eventually find a way to grow that from 1% to 33% ;) - so screw it