But how exactly do we do that other than the things I have already pointed out?
That is a difficult question to answer to say the least. I would say starve the beast, with actively refusing to further fund the feds by the people until they are willing to abide by their Constitutional duty. Or we can just cut the head off of the monster, and let the 50 states decide whether they want back into the union. Either way, it will be a messy affair, either we shed a tyrannical fed government, or we become balkanized like europe, or we end up like the USSR or china.