Evidence, witnesses, signed affidavits and experts will be presenting the case to the Federal Courts and the State Legislators.
Let’s just look at Laws governing the Elections’ outcomes;
What’s the election timeline?
The electoral college must choose their delegates and certify results on December 8th before they meet on December 14th.
The Electoral College must deliver their results to the US Senate by December 23rd. January 6th the House of Representatives and Senate will meet in joint session to count electoral votes.
Then and only then will a Congress declare a winner.
What happens if we miss the deadline?
If a winner cannot be determined by the January 6th deadline then the 12th Amendment’s “Contingent Election” applies, with each state casting a single vote determined by their delegation to the House.
As of today President Trump would readily win this form of election with 26 delegations in Republican hands to Democrats’ 23 with a tie in Pennsylvania.