Changing ExponentialHeightfog Values at runtime with Blueprint

Hey Guys. I’m guessing this is a simple thing. I just want to be able to change our heightfog values in the level blueprint as the sun moves over the sky. Unfortunately, I have no idea how to call these values in Blueprint and can’t find anybody with an explanation anywhere. I understand it has something to do with Get All Actors of Class or something. But for the life of me I have no idea how that works.

I’d really love an explanation of how to call the variables (and thus change them) of actors like these in Blueprint.