Solved How to reload world?

I'm trying to do the following:
Unload a world.
Overwrite a few files in the world directory.
Load world.

In theory this should completely change the blocks and chunks in the world.
But in reality it does NOTHING. The ONLY way I have found to get the loaded data to appear is by restarting the server, not reloading, but restarting. Bukkit.unloadWorld always returns false so maybe that's the problem. Yes, I am trying to unload the main world and there are no players online.

Edit: I am the dumbest person alive. I was trying to unload the main world...