How do I fix my game after API failing to update my scripts

I hadn't been on my game for 3 months and just found about about unity 5 so I decided up update and was greeted with API failing to update my scripts. There are 55 errors I don't understand any of them, they tell me to use Use GetComponent([less than sign]AudioSource[more than sign]() instead. There are many other errors similar to this but I guess I should start on this one. I have no idea where to put this code so I did this.

     function OnTriggerEnter (Col : Collider)
     {
         if(Col.tag == "Player")
         {
             gameObject.SetActive(false);
             GetComponent<AudioSource>();
             audio.PlayOneShot (coinSound);
             count = count + 10;
             SetCountText ();
         }
     }

The errors this dramatically dropped from 55 to 3 which were; Unexpected token: ). expecting ), found ';'. ';' expected. Insert a semicolon at the end. I have look everywhere on the internet and have had no help, surely thousands of people have had this problem when upgrading from 4 to 5, I'm afraid that when I fix this I will have to deal with 50 more, I don't want to ask 50 questions on here