The pattern is more complicated than the hat he wears. The hat he wears would be a simple 4 needle tube in 2 right/2left and it looks as if it is pulled together with an elastic yarn. I don't have knitting needles anymore but if I know how to do it, then anybody should be able to do it - I'm manually challenged all over.

BTW-you should at least control his cigarette intake if he doesn't manage to quit altogether