Presently, you can't refinance because you are not on the mortgage. The answers really depend on what type of loan that he has, FHA, VA, Conventional, etc. Changing the title is easy, and depending on what state you live in, a Quit Claim deed from him, would give you "title" to the property, but that won't remove him from the mortgage or put you on the mortgage. Contact one of our members in your state, and they will be able to give guidance.