There is no way to change that outcome in the short term. In the long term, the only way to undo the authoritarianism the court has just ushered in is to expand the Supreme Court. Democrats would have to win the upcoming presidential election and the House and the Senate. Then Congress would have to pass a law expanding the number of justices on the Supreme Court; then the Senate would have to pass that law as well, which, at a minimum, would likely have to include getting rid of the filibuster. Then the president would have to sign such a bill, and appoint additional Supreme Court justices who do not think that presidents should be kings—and then those justices would have to be confirmed.
The minority rule coup seems pretty complete with this ruling. Definitely an uphill climb for we the people.