how do you stop someone drinking to much

You don’t. I think that’s something they have to discover on their own.

I can see what your saying but how do you guide them to see their errors

They probably will stop when it becomes so pointless to drink that it does zero for them.

Whether their body will be capable of recovery, so to then their brain.. at that time, is not probable.. perhaps direct them at this post.

Liver damage affects more aspects of humanities overall ability to regenerate life force or general health than the most of us admit or know.

Guide them to this thread:

http://able2know.org/topic/182157-1

You might join a group like Al-anon. It won't stop their drinking, but it might keep you from going crazy.