How to enable children of child game object?

I'm following Quill18's Multiplayer FPS Tutorial and in Part 5 we have to enable some components in a instantiated player prefab. However, in my particular case, the player itself is a child of another GO (caller Player GO) and there's two cameras (Camera1 set to depth only and Camera 2 set to skybox) that are children of the child.

I cant enable the 2 cameras gameobjects no matter what I try. Help?

There below is my hierarchy for the player GO...

and the script that instantiates players:

 using UnityEngine;
 using System.Collections;
 
 public class NetworkManager : MonoBehaviour {
 
     public GameObject standbyCamera;
     private GameObject player;
     private GameObject camera1;
     SpawnSpot [] spawnSpots;
 
     // Use this for initialization
     void Start () {
         spawnSpots = GameObject.FindObjectsOfType<SpawnSpot> ();
         Connect ();
     }
 
     void Connect () {
         PhotonNetwork.offlineMode = false;
         PhotonNetwork.ConnectUsingSettings ("RPGVR 1.0.0");
         }
 
     void OnGUI (){
         GUILayout.Label (PhotonNetwork.connectionStateDetailed.ToString() );
         }
 
     void OnJoinedLobby() {
         PhotonNetwork.JoinRandomRoom ();
         }
 
     void OnPhotonRandomJoinFailed() {
         PhotonNetwork.CreateRoom (null);
         }
 
     void OnJoinedRoom(){
         Debug.Log ("OnJoinedLobby");
 
         SpawnMyPlayer ();
         }
 
     void SpawnMyPlayer (){
         if (spawnSpots == null) {
             Debug.LogError ("No Spawn Spots avaiables. Don't Panic");
             return;
         }
         SpawnSpot mySpawnSpot = spawnSpots[ Random.Range (0, spawnSpots.Length) ];
         GameObject myPlayerGO = (GameObject) PhotonNetwork.Instantiate("Player GO", mySpawnSpot.transform.position, mySpawnSpot.transform.rotation, 0);
         //Disable the Standby Camera
         standbyCamera.SetActive(false);
         //Enable "Sky Dome" Child of "PlayerGO" Game Object
         myPlayerGO.transform.FindChild("Sky Dome").gameObject.SetActive(true);
         //Enable Components in "Player" Children of "PlayerGO" Game Object
 
 //The camera code below does not work =(
 
         camera1 = GameObject.FindWithTag("MainCamera");
         camera1.SetActive(true);

 //Below code is okay

         try
         {
             player = GameObject.FindWithTag("Player");
 
             player.GetComponent<MouseLook>().enabled = true;
             
             MouseLook mouseScript = myPlayerGO.GetComponentInChildren<MouseLook>();
             if(mouseScript != null)
             {
                 mouseScript.enabled = true;
             }
             CharacterMotor motorScript = myPlayerGO.GetComponentInChildren<CharacterMotor>();
             if(motorScript != null)
             {
                 motorScript.enabled = true;
             }
             
             FPSInputController controlScript = myPlayerGO.GetComponentInChildren<FPSInputController>();
             if(controlScript != null)
             {
                 controlScript.enabled = true;
             }
 
         }
         catch
         {
             Debug.Log ("Error finding children");
         }

     }
 }