This is part of the documentation:
The State System is an incredibly powerful system built into the Ultimate Character Controller. Any game will have the character switching between component values as they play the game. For example, let's take a simple case of zooming the camera by changing the field of view. When the Aim ability is active it could manually set the field of view, but what if you want a different zoom for the assault rifle versus the sword? Normally you’d have to manually add a case for the assault rifle (or sword) and add that to the Aim ability so when the ability is activated it correctly switches field of view. As your game grows this would be a very tedious process. The State System simplifies this by moving much of the work into the editor and solving runtime blending automagically.
Now it does not say how to do it.
I thought this was saying in the aim ability it will activate the FOV but I tried everything and nothing is working. There is a real need for an in-depth tutorial because that short tutorial on state system doesn't tell you anything.