AS long as he is not on Edge right now, he can do an assumption of liability to transfer to new account. If the deal is current, he should be able to get it. Your account will then be free of the liability.
YMMV, but I like going to my local Verizon store for this kind of think. The folks there are all aces and I never have any misunderstandings with them. I walk away with exactly what I wanted, and often they have some great suggestions. Last time they saved me some money on my FiOS bill when all I had was a phone question.