How can i kill the Player

How can i kill this player if his or her hp is <=0

 using UnityEngine;
 using UnityEngine.UI;
 using System.Collections;
 
 public class HealthBar : MonoBehaviour {
 
     public float health,Stamina,Speed;
     public GameObject canbar , StaminaBar;
     public Text healthtext,staminatext;
     void Start () {
     
     }
     
     // Update is called once per frame
     void Update () {
         canbar.transform.localScale = new Vector3 (health/100, 1, 1);
         StaminaBar.transform.localScale = new Vector3 (Stamina/100, 1, 1);
         healthtext.text = "%" + (int)health;
         staminatext.text = "%" + (int)Stamina;
         if(Stamina > 0){
             Stamina -= Speed*Time.deltaTime;
         }
         if (health > 100) {
             health = 100;
         }
         if (health <= 0){
             Debug.Log ("Game Over");
             health = 0;
     }
     if (Stamina > 100) {
         Stamina = 100;
     }
         if (Stamina > 85) {
             health += Time.deltaTime;
         }
     if (Stamina <= 0){
         Debug.Log ("Game Over");
         Stamina = 0;
     }
     }
 }