easiest way to get rid of hornets?

Honestly, the easiest way is paying someone, especially if the nest is big, high up, or inside a wall. Hornets defend a nest much harder than wasps. If it's small, low and out in the open, wasp and hornet foam at night when they're all inside, from as far back as the can reaches, covered up, then walk away. Anyone allergic in the house - don't try it.