Restarting to play the violin? Help.. i forgot!?

Well let's see... assuming near normal functioning and a reasonable amount of time to practice, I'd suggest starting with really simple but fun stuff, say, something Suzuki book one-ish or two-ish. Let him loiter in that for a good long time (at least a few weeks!) before you start the really hard "renovation" work. Explain to him that just because it's not intellectually demanding doesn't mean that it's not helping him and that it takes time for the body to get used to playing again after so long. Also, instead of giving schradiek or sevcik to do, why not simple pieces of music that do the same thing? Above all, explain to him that there's plenty of time and that this is like renovating a house- you don't just start throwing up wallboard and randomly painting!