Folks don't change because other folks want them to, save for the rare (and not always successfull) "intervention".

This guy may be clean from heroin, but I question whether he is clean in relation to booze. Being an alchoholic doesn't mean drinking ever day, it means becoming dependent upon booze as an integral ingredient in the context of one's life...... I would suggest that LW take a sober look (pun very much intended) at his behavior patterns and see how they tie to his drinking. That, of course, can be reinforced by other "stuff" that he is using. That level of loss of inhibition control, which is, as she describes it, breathtaking, is irrevocably linked to his use of mind altering stuff.

She might try a "social experiment".... plan a weekend free of need/use of alchohol, pot, anything other than a cuppa coffee.... and see how he copes (might be interesting to see how she copes as well, but that is for her to look at). My guess is this guy can't stand to be away from his mindbending/soothing stuff for more than 48 hours, and a weekend will pretty much do him in.

Her best shot is an intervention, or something close to it: "Drop the stuff or I walk" may just scare him into another step of recovery. Howver, for her to be willing to do that, she needs to be sure that the sober boyfriend is the one she wants. She may well be infatuated with his social "charisma" that emerges whilst high, and may not like the less shiny, witty, charismatic chap that this fellow will undoubtedly be sans his "stuff".

That, of course, raises the issue of what, intrinsically, she sees in this fellow. Is it the "life of the party" or is it the thoughtful fellow buying her an outfit for a conference? My guess is that, given his reliance on mindaltering stuff, she cannot have both for the long haul. Either one has to stop for the gentle, caring chap to emerge (albiet a much quieter one) or the charismatic life of the party/brawl/police paddy wagon will squeeze out the gentle chap as he spends time in jail, rehab or a mental facility.

Alchoholism is a compelling circumstance; it grips the body in a self-destructive downward physiologic spiral while gripping the mind in a state of increasing denial. LW's father is pretty locked in, at this point in his life, and may not, actually, give a damn about stopping. The emergence of liver damage suggests that his body has adjusted to the point that, despite the debilitating impact, his body funcitons "better" on booze than while sober. (If you choose to stop smoking, you may encounter a similar phenominum at first. ) LW speaking to him about it may not change that, and if that turns out to be the case, LW will need to "let go" and understand that you have done what you can do. LW cannot forcibly stand next to him and prohibit his drinking.

If LW does speak with him, she probably has one shot, so it behooves her to be as well-prepared as possible, and turning to the local AA folks for information and support would be useful. There are a number of AA folks trained in interventional techniques, and the support of one of these folks as LW confronts her father with the consequences of his behavior would be of enormous value for her. Whether her father chooses AA as a tool for recovery becomes a different question; many folks have stopped without turning to that program, and have done quite well. Others have found the cameraderie and companionship of AA, in conjunction with the linear and consecutive nature of the step language, to be very useful in creating an adult construct of mature behavior that can lead to sustained abstinence.

LW needs to be emotionally grounded about her own reasons for intervening, and she needs to be able to let go of the consequences, which may well include estrangement from her father if he chooses to not respond to the cues from an interventional discussion. In other words, the deeply confrontational language of an intervention needs to be met with equal depth of meaning, and she needs to be prepared to act upon her statements. I note that, if he chooses to continue to drink, LW has not "lost" anything she currently has, after all, given the relatively superficial nature of their relationship. And, if he chooses to stop, she needs to be careful about her expecatations for behavioral change; I doubt that he will become a loveable old coot upon cessation of drinking, but may simply be an emotionally distant, judgemental, crotchety and crusty old sober man, instead of all of the above and drunk.

And, LW needs to buy a basic primer on alchoholism and hand it to her hubby with a sledgehammer; his casual and dismissive attitude about 'let him have his booze, he likes it so much' is an utterly naieve and superficial "take" on what is going on, and unless he trains up fast, he will be of no use at all in supporting LW in any specific action. Clearly, the man is clueless about what alchoholism is and how it works.