What options do you have when a Credit Card company files suit against you.?

I filed for bankruptcy two years ago. My ex was a co-signer on one of the cards. He made an agreement with the credit card company to pay a certain amount each month. After a while they told him he could no longer be on this plan and started demanding the full amount. They have now filed suit against him because he did not have the money they were asking for. THey said they would settle for $4,000 down and 1,400.00 per month, but he can't afford that either. Does he have any options? This is the only debt he has.