从另一个不相关的类中改变ViewController中的UILabel

I've been working on a score and highscore display for my tvOS sprite kit game. I have two classes. One of the classes is called "GameViewController," a UIViewController, and the other is a subclass of SKSpriteNode for my player. What I want to do is for every five updates, the score will update. The labels for the score and highscore are accessed via variables in my GameViewController class. In my Player class is where the updates are done, so I need to trigger a method in my GameViewController class I've been working on a score and highscore disp