How to add points upon destroying something .

i have a Level Up system script and i have an enemy script i want to make if the enemy is destroyed the experience points increases by an amount but i want all the objects that has the enemy script can i do that or do i use the tag method and thanks how can i do it i don't know how to access scripts through other scripts so please help, this is the level Up system script :

 public int level;
 public float experience;
 public float experienceRequired;
 public float Hp;    

 void Start () 
 {
     level = 1;
     experience = 0 f;
     experience Required = 200 f;
     Hp = 150 f;
 }    
 void Update () 
 {
     Exp ();
 }

 void Rank Up()
 {
     level += 1;
     experience = 0;
 }

 void Exp()
 {
     if (experience >= experience Required) 
     {
         Rank Up ();
         experience Required = experience Required * 2;
         Hp = Hp * 2;
     }
 }

} and this is the enemy script : public int health = 50;

 public void take damage(int damage)
 {
     health -= damage;

     if (health <= 0) 
     {
         Destroy (game Object);
     }
 }

and thanks