“There are, there are methods which you could do it, as you know,”
Those methods are:
Serving as VP, followed by ascension - The 12th Amendment says no one ineligible to be president can be VP, but the 22nd Amendment only bars election to a third term, not holding office. Trump could potentially be Vance's (or someone else's) VP, then that President resigns, making Trump president for a third term without being elected. This is legally untested and would be widely challenged. It doesn't seem like a route Trump would take.
Repealing the 22nd Amendment - This requires the proposal and ratification of a new amendment. This new amendment must be passed by a two-thirds majority in both houses of Congress, or by a constitutional convention called by two-thirds of state legislatures, followed by ratification from three-fourths of the states. This is an unlikely path for Trump to take. Even with massive cheating, he would never get the numbers in his favor.
Ignoring the 22nd Amendment - AKA the "what the fuck you gonna do" method, which the Trump regime has employed with great success in lots of other areas. This is almost certainly what he means.
Any other method to remain president, such as declaring martial law, declaring a national emergency, using the Insurrection Act, etc, would basically be a military coup that would spark a civil war and Balkanize the US.