How to select and deselect all objects from a list from another class?

So I have two script in my 2D game. A HomeBase script and a UnitControllerScript, where the HomeBase creates a list of units with the UnitControllerScript attached to them. So what I'm trying to do is when I click on a unit, I want to select every instance of units from that same list. How can I achieve that? Here are the two classes? Also what is the best way to select and deselect?

 using UnityEngine;
 using System.Collections.Generic;
 using System.Collections;
 
 
 public class HomeBase : MonoBehaviour {
 /// <summary>
 /// Allied base class
 /// </summary>
 /// 
 //Holds all the variables for base
 public GameObject bases;
 public GameObject tile;
 public GameObject playerUnit;
 public int garrisonSize;
 LevelManager levelManager;
 GameObject levelAccess;
 public List<GameObject> soldierUnit;
 public int health;
 public SpriteRenderer color;
 private float startTime;
 private bool isDestroy;

 float respawnCoolDown;


 // Use this for initialization
 void Start()
 {
     isDestroy = false;
     garrisonSize = 10;
     soldierUnit = new List<GameObject>();

     //Spawns starting units
     for (float i = 0; i < garrisonSize; i++)
     {
         float num = (i * 1) / 10;
          
         float angle = num * Mathf.PI * 2;

         float x = Mathf.Sin(angle) * 2;
         float y = Mathf.Cos(angle) * 2;

         Vector3 point = new Vector3(x, y, 0) + this.transform.position;

         GameObject newUnit = Instantiate(playerUnit, point, Quaternion.identity) as GameObject;
         soldierUnit.Add(newUnit);
         newUnit.GetComponent<UnitController> ().Initialize (this);

     }



     //Instantiate(tile, new Vector2(bases.transform.position.x, bases.transform.position.y), Quaternion.identity);
     color = GetComponent<SpriteRenderer>();

 }

 // Update is called once per frame
 void Update () {

     float elapsed = Time.time - startTime;

     
     InvokeRepeating("Respawn",1f,5f);
     if (isDestroy == true) {
         for (int i = 0; i < soldierUnit.Count; i++) 
         {
             if (soldierUnit [i] == null) {
                 soldierUnit.RemoveAt (i);

                 isDestroy = false;
             }
         }
     }

 }

 void OnCollisionEnter2D(Collision2D collider)    
 {
     if(collider.gameObject.tag == "Player")
     {
         Debug.Log("Player unit lenght" + soldierUnit.Count);
     }
 }

 public void Respawn()
 {
     if(soldierUnit.Count<garrisonSize)
     {
         for (float i = soldierUnit.Count; i < garrisonSize; i++)
         {
             float num = (i * 1) / 10;

             float angle = num * Mathf.PI * 2;

             float x = Mathf.Sin(angle) * 2;
             float y = Mathf.Cos(angle) * 2;

             Vector3 point = new Vector3(x, y, 0) + this.transform.position;

             GameObject newUnit = Instantiate(playerUnit, point, Quaternion.identity) as GameObject;
             soldierUnit.Add(newUnit);

         }
     }
 }
 public void UnitChecker()
 {
     
     isDestroy = true;

 }

}

 using UnityEngine;
 using System.Collections;
 
 public class UnitController : MonoBehaviour {
 
     //Variables
     public float moveSpeed;
     public float moveVelocity;
     private Vector3 target;
     private float health;
     bool active = true;
     bool isSelected = false;
 
     //Holds positions
     private Vector3 mousePosition;
     private Vector3 playerPosition;
     private float targetDistance;
 
     //Rigid body
     private Rigidbody2D rBody;
 
     //Sprite info
     SpriteRenderer color;
     private Quaternion facing;
 
     //Access variables
     PlayerController playerAccess;
     HomeBase homeBase;
     private Transform thisTransform;
 
     private bool notMove;
 
     public void Initialize(HomeBase homeObject)
     {
         homeBase = homeObject;
     }
     // Use this for initialization
     void Start () {
     
         playerAccess = GetComponent<PlayerController>();
         thisTransform = transform;
         rBody = GetComponent<Rigidbody2D>();
         color = GetComponent<SpriteRenderer>();
         color.color = new Color(1f, 0f, 1f, 1f);
         facing = transform.rotation;
         health = 10f;
     }
     
     // Update is called once per frame
     void Update () {
 
         //Reads if the user is clicking
         if (Input.GetMouseButtonDown (0)) 
         {
             //Cast a ray down to where the mouse clicks are
             RaycastHit hitInfo = new RaycastHit();
             bool hit = Physics.Raycast(Camera.main.ScreenPointToRay(Input.mousePosition), out hitInfo);
             //If it hits something
             if(hit)
             {
                 //Spits out the object's name
                 Debug.Log("Hit " + hitInfo.transform.gameObject.name);
                 //If the object is a base prints the debug message
                 if (hitInfo.transform.gameObject.tag == "Base")
                 {
                     Debug.Log ("It's working!");
                 } else {
                     Debug.Log (hitInfo.transform.gameObject.tag);
                 }
             } 
 
             //If it doesn't hit anything then say no hit
             else 
             {
                 Debug.Log("No hit");
             }
         }
 
         //Checks if health is zero to remove
         //if (health <= 0 && active == false) 
         //{
         //Destroy (this);
         //homeBase.UnitChecker(this.gameObject);
 
         //}
 
 
             Move();
     
     }
 
     public void Move()
     {
         //Sets the Velocity of the mouse
         moveVelocity = 0f;
 
         //If the user is clicking the left mouse
         if (Input.GetMouseButtonDown(0)&& isSelected)
         {
             //Sets target to the position of the mouse
             target = Camera.main.ScreenToWorldPoint(Input.mousePosition);
             //get the Z direction
             target.z = transform.position.z;
             //sets the object to be moving
             notMove = true;
 
         }
 
         //Checks if the object is not moving
         if (notMove == true)
         {
             //Move the object's position toward the target location
             transform.position = Vector3.MoveTowards(transform.position, target, moveSpeed * Time.deltaTime);
             //Get the direction of the mouse click
             Vector3 dir = mousePosition - transform.position;
             //Gets the angle calculation to rotate the object to the direction it is moving to
             float angle = Mathf.Atan2(dir.y, dir.x) * Mathf.Rad2Deg;
             //Rotate the sprite
             transform.rotation = Quaternion.LookRotation(Vector3.forward);
             transform.rotation = Quaternion.AngleAxis(angle + 90.0f, Vector3.forward);
 
             //If the object reaches the target position sets the notMove to false to stop moving
             if (transform.position == target)
             {
                 notMove = false;
             }
         }
 
     }
 
 
     void OnCollisionEnter2D(Collision2D other)
     {
         if (other.gameObject.tag == "EnemyUnit")
         {
             Destroy (gameObject);
             Destroy (other.gameObject);
             homeBase.UnitChecker();
             //Destroy(this.gameObject);
         }
     }
 
     void OnMouseDown()
     {
 
         isSelected = true;
     }
     
 }