I recommend that you call a Title Company (Ticor, First American) - Ask to speak with a Title Officer. Supply the address of the home and they will pull the lien/s and tell you how to clear it. They are very helpful .
Don't do this on your own as when you sell your home you will need it to clear title and if you don't do it right they won't insure the title anyway. They won't charge you to steer you I the right direction and they are the professionals.
Being a Broker when we encounter a lien on title or a problem we immediately contact our title officer for advice. In some cases there even security bonds that can be purchased when a lien holder disappears or you can prove payment has been satisfied.