Any credit card bills or bills that are in his name, stop paying. Are you and your child on the medical insurance? If so, you will need to contribute a portion to it. Let him know that he is now responsible for any bills that are in his name. Also, present him with the bills for your child's school/medical expenses and let him know that you expect him to pay at least half of it (doesn't mean that he will). You are responsible for your legal fees unless a judge orders him to pay those.