If someone passes out from drinking too much, you can help by positioning them so they will not choke on their vomit. If you are worried about them, get medical attention, especially if you can't awaken them to the point that they can talk to you.
The Bacchus Maneuver:
Raise the arm that is closest to you above their head. Prepare to roll them towards you.
Gently roll them toward you, guarding their head from hitting the floor. The head should rest in front of the arm, not on it.
Tilt the head up to maintain airway. Tuck their nearest hand under the cheek to help maintain head tilt and raise the face off the floor.