Please Help Convert js to c#

I have the following script and I am realy needing help geting it coverted over to c# most of my other scripts are c# and there not wanting to comunicate with js very well so I would like to switch this last script over to c#.

 var explosion : GameObject;
 var missile : GameObject;
 
 function FixedUpdate () {
     rigidbody.AddForce (transform.TransformDirection (Vector3.forward) * 200.0);
     Destroy (missile, .5);
 }
 
 function OnCollisionEnter(collision : Collision) {
     var contact : ContactPoint = collision.contacts[0];
     var thisExplosion : GameObject = Instantiate (explosion, contact.point + (contact.normal * 5.0) , Quaternion.identity);
     
         
     if (collision.gameObject.tag == "enemy")
     {
         Destroy (collision.gameObject);
         
     }
     
     if (collision.gameObject.tag == "metor")
     {
         Destroy (collision.gameObject);
         
         //Quest1.Counter +=1;
         
     }
     
     if (collision.gameObject.tag == "mothership")
     {
         Destroy (collision.gameObject);
         
     }
     
     Destroy (thisExplosion, 2.0);
     Destroy (gameObject);
 }