Need to file small claims for return of rental security deposit $2400. Landlord lives in Maryland. Rental is in West Palm beach Fl

While I can't provide any opinion as to the strength or weakness of your case against the landlord for the security deposit, if you are simply wondering how to go about filing a small claims' action, start with the clerk's website in the county in which the property is located.  Most counties in FL provide really good information regarding filing small claims' suits.  Basically, you will go to the clerk's office and fill out a "Statement of Claim" and pay the appropriate fee.  The Clerk will issue a Notice to Appear at a Pre-Trial Conference set for a specific date.  You can either hire a process server or send Certified RRR to the landlord to effect service of the Notice to Appear and Statement of Claim.  After that, many things can happen, but essentially, you'll go and the the landlord will admit, deny, or no-show.  If he no-shows, you ask for a default judgment.  If he admits, you get a judgment.  If he denies, likely you'll head to mediation.  If mediation doesn't settle it, you'll go to trial (on a later date) and attempt to prove your case.  Keep in mind a big factor in this proces - a judgment does not equal cash.  Getting a judgment enforced can be difficult.  Also, this is but a very brief and general description of the process.  Many lawyers will take on these small claims cases so you may find a small investment worth it to hire an attorney.