You'll likely have to use a collections agency to help you get the money after you get the judgement.
In the REI industry, a common firm for landlords to use is Merchants and Medical. http://www.mermed.com/
If you have the contact info for the person you're trying to collect from (which you do), it costs 25% of whatever they're able to recover. If you don't have the contact info and they have to track him down, it'* 50% of whatever they're able to recover.
If you want a direct contact, PM me and I get you in touch with one of their representatives.