There are only two ways for ending tyrannical governments. The first would be a successful rebellion immediately after the rise of a tyranny. I realize that Franco and Pinochet were authoritarian and ruthless toward their enemies, but they successfully acted to overthrow far worse Marxist regimes soon after their imposition. The same holds true for the immediate overthrow of Communist regimes imposed in the wake of World War I in Bavaria and Hungary. In an American context, this might mean secession on the part of the Southern, Plains, and northern Rocky Mountain states and an ensuing civil war with the bulk of junior officers and enlisted men in the military, especially the combat units, siding with the secessionists. However, it is hard to imagine the Republican hacks currently in the state houses in the so-called red states acting that boldly. At most, they might shake their fist at the Feds, but cave in like Orval Faubus, George Wallace, and Ross Barnett did when the Justice Department, backed up by the U.S. military, enforced school integration.
The second would be an endurance of decades of tyranny until the Marxist regime imploded from its own inefficiencies and the underlying hostility of the population, as happened with the Soviet satellite states and the USSR in the 1988-91 period. The cost in human lives, prosperity, culture, and religious life would be extremely high.