HELP - Teaching my husband to swim.

A little background. I swam competitively for over a decade starting at age eight. So, for as long as I can remember, I've known how to do all of the strokes and glide in the water. I've recently re-joined a masters team and am swimming regularly again. My husband is 6'5" and played college basketball, so he's got a stockier build. He's recently decided that he is interested in swimming for fitness as he doesn't want to gain muscle bulk but wants to get fit. I'm trying to help him learn to do actual strokes. He is capable of not drowning, but is getting frustrated because this is not "easy" and he is not naturally "good at it". I, of course, think he would love swimming (as I do) once he gets the hang of it. Our biggest issue right now is getting his body position parallel with the surface of the water. He tends to drop his hips and legs which makes breathing a challenge for him. I am having a hard time instructing him as to how to bring his hips up, in part, because it's been twenty+ years since someone taught me that. So, are there good drills I can have him do or techniques that I should be advising him about? Help!