If your ex- is going to cooperate with the process, and voluntarily sign a deed conveying the property to you, then it's a relatively simple process -- and you can likely have a real estate professional prepare a deed for you for @$250. However, if there is a mortgage on the property, the bank will need to be involved. If your ex- is a borrower on the mortgage, your ex- would be sensible to insist that he or she be removed from the mortgage (with the consent of the bank or through refinancing) before conveying the property to you. Thus, the transaction may involve fees for refinancing the property. There will also be a transfer tax for the conveyance of your ex's interest to you.

If your ex- is not going to cooperate, and there is no marriage such that the issue can be resolved through divorce, then it may become necessary to file a lawsuit for partition and sale of the property -- that can be a time-consuming and expensive process. It's best to work things out cooperatively.