He just needs some media training. There must be someone in university's marketing/comms organization who could be called in for some one-on-one work.
To be 100% honest with you, it’ll come with time. They’ll drop little tidbits and stuff to him, but it’s a comfort level of public speaking that he hasn’t had to deal with on a routine basis. If you think about it, this will be the first time a lot of these interviews will be in front of a camera/definitely not edited too. Not saying a public speaking class wouldn’t hurt, but until he’s comfortable in his new shoes and dealing with the media it won’t change.