You could file a Motion to Show Cause as to why he is not in contempt of the previous court order then reduce it to judgment. The court would give him probably thirty days to pay off the amout owed. If he did not pay he may go to jail.
In addition, depending on how your dissolution paper work reads you, may be able to collect directly from him through a garnishment of his bank account. However I would have to read your paper work prior to telling you this was the correct tactic to pursue.