Either method above works well. All you need to do is heat and it will liquify again and you can use it. It's been my experience that when honey gets to that point, it will continue to harden each time it cools, but just gently reheat it each time you want to use it. Doesn't affect the flavor.
I would heat it like KYH said, and pour the honey into a container that is more accessible to removing small amounts, that way you don't have to reheat the gal jug for every use....................ChefBillyB