Educating ourselves on what has taken place is the first thing we need to do. Taking the position in life of "man" rather than citizen is the second thing. A whole new avenue opens up just by doing that second item.
The government systems aren't designed or capable of dealing with man. Man still has rights, citizens exchanged their rights for government controlled privileges that can be taken away at anytime. That is why nearly every government form you ever fill out asks if you are a US citizen.

Think about this for minute...there is no law that says a man (or citizen even) has to be able to read yet all the "laws" are written? Common law, which is the law of the land here in the United States of America, is unwritten law has never been outlawed. We can start by challenging every court as to the jurisdiction of the court. Another thing is jurisdiction of the agencies of the government.

You mentioned the IRS . There is a group of people who have been filing suits against the IRS and obtaining court orders from the courts saying the IRS lacks jurisdiction. The key factor is that when challenged from an offensive position the IRS backs down, the commissioner of the IRS knows that they operate way beyond their limits. He doesn't dare let one of those cases be decided and a record be recorded that can be cited in future cases, if that were to happen 'the cat would be out of the bag" so to say.
Short of another civil war all we can do is expose the problems, educate ourselves and attack the weaknesses that we are able to uncover such as the IRS and the courts.
The biggest problem is to get the congress and senate to operate within the Constitution, there is where the change needs to happen. I, just like you, don't know what we can do there... voting them out only replaces them with more of the same type of power hungry folks.
We might be better off trying to get the states to take a stand but most of them are relying on federal funds of sort or another so they aren't going to be willing to bite the hand of their master.
It won't be easy but we have to try to restore this country to its former being.