“ Pelosi would be POTUS if the election was voided. Trump would not be installed is my understanding.”
There is no Constitutional method to void an election. The best to hope for is to have Biden branded as illegitimate. The political ramifications would be great.
The “Jim Crow” argument against election laws would also hit the dustbin.
The Constitution does not need to have a method to void the election. You can be damn sure that the founders would have had enough common sense and respect for the Republic that they would have dealt with fraud expeditiously. We can be no less honorable or less resolute.