Call the court clerk and they'll fax you a garnishment form to fill out. Put your judgment amount and court cost on there. Gotta find out where he works though. Depending on laws in your state, he may or may not make enough to garnish. If he makes less than about $800/mo, you might be out of luck, or you may not get the full 25% of his check, but maybe something. Call his employer after its filed and see if they'll release every pay period instead of when the full amount is collected. It's up to them, so be nice. Follow up if any check is missed, he may quit his job, or may file bankruptcy to stop the garnishment.
If you can't find where he works, try to find out if he has a car in his name that is free and clear. File at the court again to excecute on that. They may not go for it, and it may not be worth going to that extreme and amount of trouble. Plus, don't let him see you getting the VIN off of his car.
Sometimes, if you warn the employer that a garnishment is coming, they may help you to avoid the trouble of the garnishment. Back when, I had a few employers loan the guy the money and withhold it from his check, if they trusted the guy to stay. Or, they may put pressure on him for you so that you get paid up front. Call the employer before filing and "verify employment" and ask for their physical address. Talk to HR. They'll get the message, and ask you if this is for a garnishment. They may offer to help. They hate working garnishments. If he's in the military, call his CO and he'll get it done for you ASAP.
Some states don't allow garnishments, (TX) or may have limitations that can screw you. Call the court clerk for specific info. Get your judgment recorded at the Chancery Court right now, if it hasn't already been done. That is step 1.
HTH