Go back to their old programming about Hitler and Civil War (not necessarily on the same show).
Or maybe just shows about how aliens stopped the Mayan apocalypse.
The Military channel now caries those good ol’ WW2 and Civil War Documentaries.
Once the Mayan Apocalypse is averted the History channel can go back to the important business of reporting on the Swamp People, Cajun Pawn Stars, Moonshiners, and the Ax Men.