Emphasize effort, not outcome.

Tell him that you only care whether he make his best effort. In order to do so, he must follow a schedule. Remind him only once when it is time to do what.

Plan the schedule with him, starting with his current habit, say going to bed at 2am, for a week. Then 1am for the following week, etc. until it's 12 midnight.

(The problem is that his friends' habit determines his.)

You and his father must say the same thing. Work on his effort. Whatever the outcome, you two will be happy with knowing he has done his best. A child cannot have two voices in his head.