I have a dispute with a contractor I hired to build a shed. The job was not completed and the contractor wants to be paid in full. I have a written document that he agrees the job is not completed as agreed. His lawyer filed a lean on my property saying either I have to pay in full or agree to demolish the built shed. I disagree with their assessment. I believe the work needs to be completed or I should have the option to complete the job myself and deduct the cost. How can I remove the lean?