How to script mecanim turning animations?

I already have mecanim blend trees setup with my ai and they are working great except for one thing. I cannot figure out how to play the turning animations through scripting. I have tried using the stealth tutorial but I cannot figure out exactly how it works. I am using the parameters move speed and angular speed in my blend tree. Using the move speed was pretty straight forward but how would I change the angular speed parameter to update the blended animations? Here is the script I use to change the forward speed atm.

 var rexAnimator : Animator; 
 var currentSpeed = 0f;                                //   movement speed variable.
 var lgCarnAction : LgCarnActionManager;
 
 private var lastPos : Vector3;
 
 function Start() 
 {
     rexAnimator = GetComponent(Animator);
 }
 
 function Update() 
 {
     var currentMovement = transform.position - lastPos;
     currentSpeed = currentMovement.magnitude / Time.deltaTime;
     lastPos = transform.position;
     
     rexAnimator.SetFloat("MoveSpeed",currentSpeed);
     

}