I have co-signed on a truck for a friend. He did not pay the loan and the car was repossessed. He will not answer the creditors phone calls. We are no longer talking and I have been cooperative with the creditor giving them any information that they need to find him. I co-signed on the truck but they keep saying that I am the main borrower. I have emails from my ex friend stating that I was the co-signer. Is there anything I can do to change me to the co-signer and make my friend the main borrower so that I don't receive as many harassing calls?

The reason that the creditor required your "friend" to have a co-signer was because they were concerned that he would fall behind on payments, which is precisely what happened. When you agreed to co-sign, you guarranteeed that you would pay if he didn't. Obviously in hind-sight this wasn't in your best interest. So no - they will continue to harass you until either you or he pays the outstanding amount. I suppose you could pay off the remaining balance and then sue him in small claims court.