Drew currently walks 2 miles every day after school but wants to take his work out to the next level which of these changes would you suggest he make to his routine to increase his stamina

Drew could start jogging at a slow and steady pace. Once his stamina level increases by the jog, he could then increase his speed. But it should stay at a jog if you don't want to be all sweaty at school, lol.

Yes, this is very true. specifically causing damage in the  dentrite.