Offer them "cash for the door" where you say to them I will pay you to pack up nicely and leave, even pay for their moving van! This can save you from having to deal with a mess on the property and damage.

Unlike most other states, Florida does not have a specific procedure to remove squatters. You can file an “unlawful detainer lawsuit.”

Although not required to do so, it is advisable for an individual intending to file an unlawful detainer lawsuit to provide the squatter with the notice of your intentions. This may compel the squatter to leave, and avoid the need to file an unlawful detainer lawsuit. The notice can contain for example: a verbal warning, as there is no requirement that the squatter be notified prior to the unlawful detainer suit, the owner can provide verbal warning of their intention to file suit, and demand the squatter vacate the premises, although it is likely advisable that any demand to vacate also be communicated in writing.
A Letter: An informal letter mailed to the address may be used to notify the squatter of your intentions.
Posted Notice: If a more formal manner of notice is desired, the property owner can serve the tenant with notice in the manner required by formal eviction actions.
If the squatter refuses to adhere to the notice, you will have to proceed with filing an unlawful detainer lawsuit. (Tony PO Staff)

I was going to sugest Cash for Keys, which is something I learned about at a recent reia meeting. Seems like a good solution.

How do squatters access the property in the first place?
And, after you pay them off, what's to stop them from coming back to the property at some point in the future?