Claim the other 1/2 of the country DID NOT vote for your opponent but instead claim the vote is fraudulent and you actually won the election.
Use your campaign team to flood the battleground states with lawsuits hoping one of them will land with a sympathetic judge who will rule in your favor.
Consult with the Republican leadership in battleground states and remind them of the laws in their respective states about certifying their elections.
Inform the Republican state leadership of what they should do within their state if they think the certification is false in some way. Perhaps they need a second election. Or perhaps they can select the electors with their majorities in their legislature and send the Electoral Certification of the Vote and Certificate of Ascertainment to the Archivist and the President of the Senate by voting within the legislature.
Continue your efforts to win even if it means thwarting the votes of the American people. After all, almost half of them voted for you and they will not complain about what you did.
Continue to use your personal attorney to distract the news media while your team plans other approaches to continue your reign.
Recognize that there are six ways to have this end up in the Supreme Court for a decision that favors you. Make one of them happen.
Never Surrender. Never Give-Up. You are Trump and you are Supreme.