Fla. Stat. § 88.6161

A party or support enforcement agency seeking to modify, or to modify and enforce, a foreign child support order not under the convention may register that order in this state under ss. 88.6011-88.6081 if the order has not been registered. A petition for modification may be filed at the same time as a request for registration, or at another time. The petition must specify the grounds for modification.