If there is a landlord-tenant relationship, the proper cause of action in Florida is an eviction action.

If there is not, you bring an action for ejectment or wrongful detainer.

The background of the case, and the allegations made by the occupant, may affect your ability to succeed with one form of action or the other. An ejectment must not resemble a landlord-tenant relationship -- so if the occupant claims that he paid rent while the life tenant was alive, or made contributions that amounted to rent, the ejectment action may be deemed improper by a court; but if you bring an eviction, he may attempt to stall for time by claiming that there was never any form of relationship that could be construed as landlord-tenant.

If it were me, I would find a real estate firm and have the law firm review the facts, advise on a course of action, and handle the eviction / ejectment process.