I had 2 interventions in my life and neither worked. In fact, they made it much worse for me.
I suggest that you go to AlAnon and learn a bit about alcoholism before trying anything (btw, AlAnon is not AA, but is a program to help non-alcoholics understand what they’re dealing with.)
Your friend is lucky to have you. Don’t give up on them. It truly is hellish, and they’ll need your support.
If you just want it to work, and you’re coming from Windows or Mac, use Ubuntu. It’s a nice intro, and the hardware support is excellent.