Can I get out of Co-Signed Loan

I co-signed on an auto loan 21 mo's ago. I was assigned as the primary due to a better credit rating. I have since severed ties with the co-signer. She has possession of the vehicle and stopped making payments about 4 mo's ago. I have been making the payments, but this is a great financial strain. I want to know if it would be possible to take legal action to have my name off of the loan agreement.

The lender would have to agree--but you can sue her if she fails to pay.

I made a poor choice on co-signing for a auto loan for my brother and he in turn sold the vehicle cheaper than the loan was and used the money for something else. The person driving the vehicle doesn't have a title. I want to get out of the loan because they want to garnish my wages. I am taking my brother to magistrate court but I don't know what that will do. He is useless in getting any funds. He doesn't work. What do I do? I do not want this on me and I was very young when I made this choice and had no idea it would affect me and my credit. I am trying to start a family and can't until this is over. what do I do? Please help.