It is different in each state.
Go to the court house where the work was done and ask the clerk. Lawyers will want around 1/3 to go to court to get a "judgment" and will want more money to collect. You try to include this plus interest when you ask the court for the judgment. Sometimes you can prove "fraud" and collect "punitive damages" and collect more as apunishment for illegal acts.
Do not threaten any legal action.Just do it!
In general a "lien" stops property from being sold until you get your money. The trick is to find money or assets to "attach". Identify any bank accounts used for checks to you. Identify any vehicles or other property.
Ask who does collections in your area.
Good luck,
Joe