How Can I settle this two year judgement the attornyes are a

I have a judgement and I owe american Express $6,400 their attorney has been very aggressive and now they are asking to subpoena business record from the creditor that my mother in law is helping me make car payments to. My husband is the one whose name is on the credit for the car loan and I signed as his wife. I don't want to cause my mother in law any creditproblems that may show on her records .What can I do now to settle with them do I need an atttorny to deal with them they are very aggressive and threatening. My mother in law wrote to them and I wrote a letter to them allowing her the right to help me resolve this matter. Can they make my husband liable for my debt.