Change the scale with OnCollisionEnter

When my player collided with a button"GAMEOBJECT" change the scale to big and the button is actived
When i collide again change my player scale to small and the button is disabled.
How can i do that?

//My player
public GameObject Player;
//Materials
public Material[] material;
Renderer rend;
void Start()
{
    //RenderMaterial
    rend = GetComponent<Renderer>();
    rend.enabled = true;
}
private void OnCollisionEnter(Collision coll)
{
    //Change to Big
   if(coll.gameObject == Player)
    {
        rend.sharedMaterial = material[0];
        Player.transform.localScale = new Vector3(5, 5, 5); 
    }
   //Change to Small
   if (coll.gameObject == Player)
    {
        rend.sharedMaterial = material[1];
        Player.transform.localScale = new Vector3(1, 1, 1); 
    }
}

}

private int collisionsCount = 0;

 private void OnCollisionEnter(Collision coll)
 {
    if(coll.gameObject == Player)
     {
         collisionsCount++ ;
         //Change to big when the object collides with the player the 2nd, 4th, 6th, ... time
         if( collisionsCount % 2 == 0 )
         {
             rend.sharedMaterial = material[1];
             Player.transform.localScale = new Vector3(1, 1, 1); 
         }
         //Change to small when the object collides with the player the 1st, 3rd, 5th, ... time
         else
         {
             rend.sharedMaterial = material[0];
             Player.transform.localScale = new Vector3(5, 5, 5); 
         }
     }
 }