Transfer a F-Visa into a Student X type? Do I need to leave the country?

Hey, I'm currently on a F-type (Single Entry, 180 Days) and I'm planning to sign up for a language school so I can get a Residence Permit/Student X type and travel more which I can't with my current F type. Questions is, do I need to leave the country or can I apply within the country once I have the documents? I have different stories that they can easily change your F-type to a student X type, but I also have heard other stories. Any ideas? Thanks heaps.