Your AH is determined to drink himself to the grave. Liver failure has already happened. Why waste time dancing around the obvious issue?
Lay it all out.
Also, have a contigency plan for yourself (i.e. place to go, money put aside, important docs safely stashed away somewhere OTHER than the house). Expect him to dig his heels in and make your life impossible. You're about to pull the rug out from under him...BUT he's an adult and he's made his choice. He can now live (or die) with them.