Here are some tips on how to help and approach a conversation:
GENERAL HELPING SKILLS:
Talk to them in a private space when both of you have time and are not rushed or preoccupied.
Be direct and specific about your concerns. Express your concern in behavioral, nonjudgmental and caring terms. For example, "You look stressed. I'm concerned about you. Can you tell me what's going on?"
Be aware of campus resources and make a referral to someone in a position to help. (SJU resources)
Follow up with your friend. Check in with them later to find out how he or she is doing.
Provide appropriate support, but know your limits and who else can help.
TALKING ABOUT ALCOHOL USE:
It needs to be well-timed: Don't confront the person when they are drunk or high.
Be informed: Know the dangers of drinking to excess, how to drink at a low-risk level, and resources for support. (Alcohol Resources)
Discuss alcohol issues openly: Letting the person you are concerned about know that you are open to listening to them without being judgmental.
Don't expect change immediately: Be supportive, but don't help or "enable" them to continue with the problem.
What to Expect:
A lot of excuses
Attempts to change the conversation
Attempts to minimize the behavior as "No Big Deal!"
That you can make a difference.