How could someone actually turn US into a dictatorshiop?

US has a strong system checks and balances, so if the president actually wanted to overthrow the political system and become dictator, how would he even do that? Changing the constitution is too hard to do. The closest thing I can think of would be if he had a sufficiently loyal party in mayority in congress, to pass the law changing the number of Justices on SCOTUS from 9 to 1, just the Chief Justice that Constitution requires, then somehow get rid of all Justices on Court one way or another, perhaps blow up the plane they are all on, and nominate himself as Chief Justice. Then he would continue being both President and Chief Justice, there is some precedent as John Marshall was for a time both Chief Justice and secretary of state. This, due to him being only Justice on Court, would give him both full judicial power and as president full executive power.

Any order he made, if it gets blocked at the lower court, would ultimately end up back to him on SCOTUS, where he would reverse lower courts and establish any precedent he wants that lower courts would from then on have to follow. As sole Justice, his word would be the law of the land. Constitution and laws say what he says they say. He could even rule that congress cannot impeach him unless he commits crime, reversing ruling that said impeachment is a political process. This is the easiest way I can think of for the President to become the modern Roman Emperor. What do you think, is there any other way?