The BACCHUS Maneuver|
If someone you know is drunk almost to the point of passing out, you may want to help put them to bed for the night. If so, make sure you do them a favour and know the BACCHUS maneuver, reducing the risk of choking if they throw up.
Your friend may also need more than just time to sleep it off. If you are at all worried about the state they are in, get medical attention and don't leave them, especially if you can't wake them up. They may have alcohol poisoning and need to be hospitalized. They may have injured themselves in a fall, or combined alcohol with other drugs. They may even have a medical problem that you do not know about.
This procedure (shown in diagram) is based on a well known first aid treatment.