How do you show someone that they have a "problem"?

one of my very close friends, i think is an alcoholic..

he drinks every single day, and gets completely drunk, way beyond what he calls just for fun. he tends to call me at these times, four in the morning and i have been given the nickname “kayleigh bug” because he likes to bug me.

last night he called me BEFORE he went out, and said that he was tiered and was going to take a shower and i suggested that he stay home, and get some sleep. he then proceeded to lecture me about how if he skipped that night, it would be one day less of his life that he could have been drunk.. we then argued about him being tiered and i tried to convince him to stay home and sleep, but he went out last night still.

we got on the topic of alcoholism and he said “I am not an alcoholic. we aren’t even going to go there. I may have an addiction to like captain crunch, yes I’m a Cheetos addict, but no NOT drinking.”

he doesn’t see it as a problem, but i do. he makes horrible decisions and has driven after he had been drinking. I just dont want anything horrible to happen to him, or anyone else, so how do i convince him that he should change his ways before he gets hurt, hurts someone else, or gets in a lot of trouble?