how do i collect arrears for my 2 kids?

Well, you can get paper judgments, but if there is nothing to "get," it is hard to see how you can actually collect anything.  On the other hand, relatively few people actually live in cardboard boxes with no income, assets, etc. You could file a motion here, asking for arrears to be reduced to judgment, and for an order to show cause why he should not be held in contempt for non-payment.  "Impossibility" is a defense, but unwillingness to work is not.  He may appear here; he may ignore the action here. You can then domesticate (register) your decree and order reducing arrears to judgment in the place where your ex lives and have him hauled into court THERE -- the place where he lives would be able to do an examination of judgment debtor, take driver's licenses or other such away, or even incarcerate for willful contempt of support obligation.