how can i help someone who is trying to quite smoking weed?

i don't consider it as serious as crack cocaine or acid or heroine, etc., but i AM trying to help my husband quit for this new year and help him deal with it. he's not gone a week without weed for the last 10 years - it's only been 2 days and he's itching for some. how can i get his mind off of it and help him move forward?
yep, i'm getting the yelling and overall bad mood from him already, but at least he does want to quit for himself, which is what i wanted as well.