If someone violated probation, in Florida. Had probation time added, with the stipulation of a guardian. Is there a way to change the guardian, if that person keeps threatening you with violation if you do not do what they say and want?

Speak with your probation officer. It should be easy enough to do, especially if the things being asked of you are unreasonable (to an outsider)

Be sure to have a sbustitute guardian standing by who will pass scrutiny of the PO. You should be able to change the guardian to meet the probation requirements.