How can I take over the loan and ownership of my car?

My ex-girlfriend and I had went in together on the purchase of a car. I've been the one making all the payments, without a single dime from her. That probably wouldn't matter regarding this issue, but...I'm the co-signer, and I would love to just take over the ownership and payments of the car. I mean, c'mon, we broke up and just don't want to have anything to do with each other. Because she's the primary "owner" on the contract, and loan (again, I'm the co-signer), is there any way I can just remove her from the loan, and ownership? I've actually been the one who's been driving the car since day one, and even the insurance is under my name? Someone help me please!!!! I don't want any more demons from my past coming back to haunt me, and even threaten to take the car away from me when I'm the one whose made "every single" payment! Help me, get her out of the contract, loan, and off my back!!!!