First, if a majority of people did not vote for you, proclaim that the election was tainted. Add that millions of those who voted against you were not Americans but illegal immigrants. Against all evidence, continue to make this claim
Second, if some media reporting is critical of you, angrily denounce these critics as the opposition, or even that the free press is the enemy of the American people.
Third, if reports are leaked that a foreign power may have interfered in the election that put you in office, deflect attention from these reports. Loudly state, showing no evidence, that the past president ordered illegal wire taps. Order your administration to continue to push your accusation, throwing as much sand as possible into a clear investigation of possible foreign meddling.
Fourth, turn citizens’ healthy skepticism of government into hatred. Proclaim often that government is the enemy. Appoint amateurs into positions of leadership, declare a hiring freeze, and starve the government of funds, assuring lack of expertise when crises arise.
Coups do not necessarily require troops marching in the streets. Small groups can so manipulate emotions by sound byte slogans and angry rhetoric that the electorate begins to believe them. It they succeed, they will prove the old adage that a lie repeated often enough will be believed.