Space Shooter Highscore GUI scripting help C#

After maybe a hour of creating a script for the space shooter tutorial that unity made i finally got it to the point were i don't have any errors but i am confused on how i can make it work with the Done_GameController Script so i can have a GUI text pop-up by the score and display the high score. So is there a way that i can fix it or that i could combine it.

Code (CSharp):

1.  
2. using UnityEngine;
3. using System.Collections;
4.  
5. public class Done_GameController : MonoBehaviour
6. {
7.     public GameObject hazard;
8.     public Vector3 spawnValues;
9.     public int hazardCount;
10.     public float spawnWait;
11.     public float startWait;
12.     public float waveWait;
13.    
14.     public GUIText scoreText;
15.     public GUIText restartText;
16.     public GUIText gameOverText;
17.    
18.     private bool gameOver;
19.     private bool restart;
20.     private int score;
21.     private HighScore HighScore;
22.  
23.     void Start ()
24.     {
25.         GameObject HighScoreObject = GameObject.FindWithTag ("GameController");
26.         if (HighScoreObject != null)
27.         {
28.             HighScore = HighScoreObject.GetComponent <HighScore>();
29.         }
30.         if (HighScore == null)
31.         {
32.             Debug.Log ("Cannot find 'HighScore' script");
33.         }
34.     }
35.  
36.     void OnStart ()
37.     {
38.         gameOver = false;
39.         restart = false;
40.         restartText.text = "";
41.         gameOverText.text = "";
42.         score = 0;
43.         UpdateScore ();
44.         StartCoroutine (SpawnWaves ());
45.     }
46.    
47.     void Update ()
48.     {
49.         if (restart)
50.         {
51.             if (Input.GetKeyDown (KeyCode.R))
52.             {
53.                 Application.LoadLevel (Application.loadedLevel);
54.             }
55.         }
56.     }
57.    
58.     IEnumerator SpawnWaves ()
59.     {
60.         yield return new WaitForSeconds (startWait);
61.         while (true)
62.         {
63.             for (int i = 0; i < hazardCount; i++)
64.             {
65.                 Vector3 spawnPosition = new Vector3 (Random.Range (-spawnValues.x, spawnValues.x), spawnValues.y, spawnValues.z);
66.                 Quaternion spawnRotation = Quaternion.identity;
67.                 Instantiate (hazard, spawnPosition, spawnRotation);
68.                 yield return new WaitForSeconds (spawnWait);
69.             }
70.             yield return new WaitForSeconds (waveWait);
71.            
72.             if (gameOver)
73.             {
74.                 restartText.text = "Press 'R' for Restart";
75.                 restart = true;
76.                 break;
77.             }
78.         }
79.     }
80.    
81.     public void AddScore (int newScoreValue)
82.     {
83.         score += newScoreValue;
84.         UpdateScore ();
85.     }
86.    
87.     void UpdateScore ()
88.     {
89.         scoreText.text = "Score: " + score;
90.     }
91.    
92.     public void GameOver ()
93.     {
94.         gameOverText.text = "Game Over!";
95.         gameOver = true;
96.     }
97. }

Highscore script

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.    
4. public class HighScore: MonoBehaviour
5.     {
6.     public bool levelComplete;
7.     public string highscorePos;
8.     public int score;
9.     public int temp;
10.     private GameController gameController;
11.  
12.     void Start ()
13.     {
14.         GameObject gameControllerObject = GameObject.FindWithTag ("GameController");
15.         if (gameControllerObject != null)
16.         {
17.             gameController = gameControllerObject.GetComponent <GameController>();
18.         }
19.         if (gameController == null)
20.         {
21.             Debug.Log ("Cannot find 'GameController' script");
22.         }
23.     }
24.        
25.     void OnStart ()
26.         {
27.             score=0;
28.         }
29.        
30.         void OnLevelComplete ()
31.         {
32.             levelComplete=true;
33.             score=10000; //values from your scoring logic
34.             for(int i=1; i<=5; i++) //for top 5 highscores
35.             {
36.                 if(PlayerPrefs.GetInt("highscorePos"+i)<score)     //if cuurent score is in top 5
37.                 {
38.                     temp=PlayerPrefs.GetInt("highscorePos"+i);     //store the old highscore in temp varible to shift it down
39.                     PlayerPrefs.SetInt("highscorePos"+i,score);     //store the currentscore to highscores
40.                     if(i<5)                                        //do this for shifting scores down
41.                     {
42.                         int j=i+1;
43.                         PlayerPrefs.SetInt("highscorePos"+j,temp);  
44.                     }
45.                 }
46.             }
47.         }
48.        
49.         void OnGUI()
50.         {
51.             if(levelComplete)
52.             {
53.                 for(int i=1; i<=5; i++)
54.                 {
55.                     GUI.Box(new Rect(100, 75*i, 150, 50), "Pos "+i+". "+PlayerPrefs.GetInt("highscorePos"+i));
56.                 }
57.             }
58.         }
59.     }

Thanks in advance.