I don't think it's tough to change his status from b1/b2 to f1. Matter of fact, I was here in the state with my b2 tourist vissa for 6 months. After 3 months, i change my status to f1 through community college and it was approved with in another 3 months.
he can only change status to f1, if he needs vissa he needs to go to out of states to apply.