Good for training sake. Get him with OFFA or a similar group and start doing the 5v5 stuff. Lots of exposure at those (even more than the 7on7 on some ways).
Camps. Camps. Camps. He should go to as many as possible this summer. Focus on the ones that have Big Man specific camps and padded ones.
Then Twitter. Twitter. Twitter. Contact coaches.
Send film.
Then call up campuses and ask to come visit. Most of these Unofficial visits you see on Twitter are instigated by the recruit.