Grochach

Hello, My girlfriend is a B2 visa holder currently, she is south african. She is trying to get into school here in Miami, I would like to know what is the best way to transfer or apply for a new visa. 1: she is already in the states, how would she apply for a new F-1 who is the best contact 2: is it better for someone who is traveling to just transfer from one to the other or apply for a new one. ( I read a thread where you had said that a transfer doesnt last when you leave and return. 3: anything I should know about the process? or a thread that might help?