How to quit cannabis, is there nhs help?

my partner has been smoking cannabis for the last 10years, he has now come to the decision it is ruining his life and wants to stop, however after smoking everyday for the last 10years he's finding it hard, he wants to stop but his body still needs the drug, has anybody quit and how did you do it, also is there any help the doctors can give him, they help heroin etc users but they don't seem to help cannabis users, no sarky answers please iv heard them all before! thanks