How to Access MouseLook In Unity 5 with JavaScript

I'm following a tutorial to make a horror game. In the 8th tutorial I got stuck with the Mouselook option, he is using an other version of unity and I'm using Unity 5.

In Unity 4, MouseLook was a script attached to FPController, but in Unity 5, MouseLook has changed to become a part of FPController Script (in C#) as an object.

Now I need to access that, how to do that?

The file I am using is here: http://ryandome.weebly.com/ (named pausemenu.js)

And the error is in line 238 where it's unable to get the FPS controller's Mouselook option:

firstPersonControllerCamera = gameObject.Find("First Person Controller").Find("FirstPersonController");
print(firstPersonControllerCamera);
mainCamera = gameObject.FindWithTag("MainCamera").GetComponent("MouseLook");
firstPersonControllerCamera.enabled = false;
mainCamera.enabled = false;