@rallenwriter -- The only thing that I've ever found that works are those long-distance sprays, but even using those take some technique.
The first thing you need to do, before you even start to remove the nest, is to make sure that you're dressed properly -- long sleeves, long pants, a drape over your head, gloves and boots are a must.
Then, wait until nightfall, when all the hornets are in the nest, and go underneath and slightly to one side of it. If you stand right underneath it, then it's more likely that a hornet will fall onto you and sting you.
If you do shine a flashlight on the nest, make sure it is through a red filter, so you don't disturb the hornets.
Then, spray away until they're all dead. Honestly, even if you think they're all dead, it doesn't hurt to wait a little and then spray some more -- you really don't want to mess with these guys, they're nasty.
If you still have hornets after that, then you're probably going to need to just call an exterminator.