How can I get my name off a mortgage?

My husband and I have recently decided to purchase a home. I'm a stay at home mom and he works full time. He has a near perfect credit score of 785. When he went to the bank to see what we qualified for, he discovered that his name is still on the mortgage for the condo he owned with his ex wife 3 years ago! Apparently he thought he handled the situation then, but he found out he only put her as the title holder and the transaction that took place did not remove him from the mortgage. She is still living there and has been making consistent payments which is why we haven't discovered this sooner I'm guessing. I'm sure she has no idea about this at alll. They were young and dumb and had no lawyers involved in the divorce. We were told we have 2 options: Attempt to have her re-finance the loan to see what she qualifies for and have it put in her name. My husband is afraid because of her bad credit she won't even qualify for the loan and it will be a waste of time. We don't want the condo because the payments are 1500 a month and right now we pay about 900 a month. There is no way we could even afford it if we did take it over. Or the other option was...run out and quickly buy a home now (with a co-signer) and deal with her after we are in a house so that way if she were to lose her job or stop the payments we would at least be in a home and his credit would be hit hard after we were safe in our new place. We could kick her out and foreclose on the property if worse came to worse. Both options scare me and I'm hoping someone out there has some insight on how this could be handled? There has to be a way out of this mess! Can anyone PLEASE give a stressed lady some advice! I would appreciate it so much!! Thank you!!!