The vote of the electors is on Dec 17th. Their refusal to vote for Donald Trump, while potentially illegal, would actually be binding. The incoming Congress could still flip the result back, but that would also be illegal. The states choose electors and the electors choose the President. Full stop.

So how would we convince electors that are almost always party loyalists? Give them a preview of a Trump presidency. Deport immigrants NOW (or preferably they GTFO on their own), raise tariffs NOW, stop enforcing regulations NOW, start Trump policies right NOW! Make this the worst Thanksgiving in a decades and make Christmas look just as bleak. Once he's in the only way Trump will leave is voluntarily (ha!) or if one of his hirelings stands up to him.