Or just claim fraud, and refuse to leave. See if the military will back you or not. He's got 4 years to keep weakening institutions and installing loyalist generals.
One would be causing red states to vote their Electors for Big Bird or whatever, thereby ensuring that “no Person have a Majority” of electoral votes [1], thus punting the Presidency to the House. (That or having Vance just throw out “bad” votes, again, throwing the election to the House.)