Had mine out when I was eighteen... was very fragile for a week or so, and still a bit weak, sore and sorry for myself the week after. I could talk the day after - but only because a stupid nurse SHOUTED at me 'what's your name' about ten times without looking at the chart to see I had had tonsils removed the day before. This was in the days when they gave you soft foods for the first few days, I would do that even if the hospital has other ideas, because it really hurts, and why should you aggravate it, it will heal in a week or so and diet will be back to normal. Lots of painkillers, lots of rest, lots of fluids and lots of TLC.
Wish him all the best with it.