You can choose to become one through Aigae courses or through the Regulated Regions. If you have a qualifying degree, you can request to take the exam directly in the Tuscany Region. But I strongly recommend that you always take the course. If you are already a Tour Guide or Tour Leader you have direct access to the GAE exam in Emilia Romagna, but then you won't be able to register for Aigae because you have to take a course.