To night Train a 5 year old you can cut off liquids after a certain point in the evening and make sure your 5 year old goes potty before bed every night.
Set an alarm for 3 hours after the 5 year old goes to sleep and wake the 5 year old up to try and pee.
During the night training I would still recommend that you have your 5 year old wear a pull up or diaper to help keep his pajamas or clothes and bedding dry.
Wetting the bed is very normal in kids and is not usually a concern until 8 or older.
However some kids continue to wet the bed until age 17.
I personally wet the bed from 5 years old up until 17 and my parents took me to the doctor and they said even after 8 it was still normal.
Eventually just a few days after I turned 17 I stopped wetting the bed and am very healthy.
Until then I wore diapers to help keep my bed and clothing dry.
Diapers do not cause any issues with bed wetting and the diapers don't cause the bed wetting.
Some kids can be night trained to wake up and go pee at night and others cannot and will continue to wet the bed and a diaper or pull up will work great to keep your child happy and healthy and help them get a better nights sleep.