Hello,
1. Talk to the contractor. If you believe the unpaid work the lien was claiming was actually paid, the contractor can remove it themselves. Or you both can reach an agreement on the value of the work and you can pay that way.
2. Sue them for an invalid and unenforceable lien. This is a full lawsuit requiring petition, discovery, depositions, motions, and the like in District Court so you should consider contacting an attorney for the specifics of your case.
E. Aaron Cartwright III
214.789.1354
Aaron@EACLawyer.com