You file a lien by recording your judgment with the county recorder. It's a pretty simple thing to do in most states.
But what do your tenants own that would be worth getting a lien against? If there property interests are all exempt under state laws, you have just put out money on recording fees to get what - nothing!
Check state law for more information on exemptions in your state. Most states post the laws on the state website.
Disclaimer: This answer does not constitute legal advice. I am admitted in the States of New York, New Jersey and Massachusetts only and make no attempt to opine on matters of law that are not relevant to those three States. This advice is based on general principles of law that may or may not relate to your specific situation. Facts and laws change and these possible changes will affect the advice provided here. Consult an attorney in your locale before you act on any of this advice. You should not rely on this advice alone and nothing in these communications creates an attorney client relationship.
Recording the judgment lien will perfect the lien as to real property only. A lien against personal property only attaches from the date of levy against the property. RCW 4.56.190. Recording the judgment won't give you a lien against personal property. You have to levy against the property by execution or garnishment. If one of the tenants has a steady job, a wage garnishment may be the easiest and least expensive way to collect. You should have an attorney assist you with collection of your judgment.