Only way he wouldn’t shut it off, and roll over and go back to sleep 😴.
That’s what I do - set the phone in the other room, so I have to get up to turn it off. However, most mornings I am already awake, as my son gets up at 4:00 to go to the gym. If his alarm doesn’t wake me up, he usually bangs about 15 things in the kitchen getting his “power drink”. Hard to get mad at him, as he is pretty dedicated, but some times it’s like “Damn, come on kid”!
That’s exactly what I had to do as a teen. Then the snooze button was invented, and I hailed that as one of the greatest inventions of all time!