Can you tell me, how are people advised to talk when confronting an alcoholic?

There is no "pat": Answer to this question. In general, I do not advise friends or family to "confront" people with alcoholism, since they usually have greatly developed denial, and will almost always react with anger and resentment, and it will even increase their level of denial. Being open, honest and caring, avoiding labeling and insults, avoiding loaded terms like alcoholic (better-problems with alcohol) best.