How do you nighttime potty train a 5 yr old boy?

To nighttime potty train a 5-year-old boy, start by ensuring he uses the bathroom right before bed. Limit fluid intake in the evening to reduce the chances of nighttime accidents. Use waterproof mattress covers and have extra sheets handy for easy cleanup. Encourage him with positive reinforcement for dry nights, and be patient, as nighttime control can take longer to develop than daytime training.