The answer to your question will depend on the state in which you live. If you are in Indiana I can tell you that filing a small claim is as easy as walking into the courthouse, remembering your name, and remembering who you want to sue. Whether you can get prejudgment interest is a matter of discretion of the court, so I wouldn't hold my breath for that. But if you're not in Indiana then just take this as general guidance and speak with an attorney in your area.
Best of luck!