How to get a writ of garnishment issued in federal court?

I obtained judgment against a defendant in one federal court and registered it in the US District Court for the Northern District of Illinois. I know where this defendant has a bank account and want to have the court issue a writ of garnishment to serve on the bank so I can get paid. Do I apply for the writ and the court will execuite one? There are no federal forms on the court's website in this regard. Do I have to use the procedure as in Illinois state court (affidavit for garnishment, get a summons for garnishment to garnishee, etc.)? How can I do this without federal forms (Cook county has state court forms). Any help would be appreciated!