"I am afraid there is not really a way other than to not enable the drinking and not tolerate the behavior that results from it. An alcoholic has to be left to suffer the natural consequences of their actions. They have to want to be sober and consequences can lead to the proverbial bottom."

I agree with this, but you can also think of the ways the enabling is happening and work with the family to eliminate it. The family has to be willing/able to follow through and able to tolerate conflict, which is almost always the result of trying to get someone who doesn't want to change to start changing.
There is another resource available via Robert Meyers, PhD: He has a program called, "CRAFT" and has written a self help book on the subject as well. https://www.robertjmeyersphd.com/craft.html