We put the belt on just before he gets on the bus. It wraps around his winter jacket and under his backpack. He puts it in his backpack and his principal puts it on him to help him on the bus at the end of the school day. I hope this helps. If there's any other questions, let me know.
BTW, our bus driver just went to see the bus the other day. He was really impressed. I'll see it on Monday.