You can ask your former partner to sign a "quit deed" and get the property title out of their name and into your name. Therefore you have the deed and the mortgage on the property in your name. At that point you can sell, refinance, or whatever you would like to do. Good luck!
Contact a few investors and agents to see who comes up with the best plan.
The problem is that the deed is in his name and the mortgage is in your name. The lender will go after you for the money. I agree with the other agents about getting a lawyer, but when it comes down to it --- Your name is still on the mortgage and his name is on the deed. You will have messed up credit if the payments are not made. The best thing to do is to sit down and talk to your partner to see if you two can work out this problem. Ask him to refinance the home and put the mortgage in his name or see if he'll quit claim the home over to you. You then will be able to rent the home out or move into the home. I'm sorry that you are going through this.