How can you over turn an election that is incomplete?
Pence can just refuse to accept the electors in the seven contested states of Arizona, Georgia, Michigan, New Mexico, Nevada, Pennsylvania, and Wisconsin who have sent dueling slates of electors to D.C. Since they violated Article II, Section 1 of the US Constitution by not following their own state constitutions in conducting their elections, the electors' votes submitted should not be considered because they are illegal.
He doesn't have to even accept and count the alternative slate of electors for Trump sent in by the state legislatures. He only has to count the electors from the remaining states.
If the votes of all seven contested states are registered as zero, President Trump would have 232 votes, and Joe Biden would have 222. The 12th Amendment says, "The votes shall then be counted.... The person having the greatest number of votes for President, shall be the President."
In plain language, Donald Trump will be re-elected, since he has a majority of the actual electoral votes that are legal. There will be no need to involve the House of Representatives to resolve a contingent election.