Did you go online and check what the Ministry says ?
https://www.ontario.ca/page/health-card-renewal
If he can’t do it online then he goes into an OHIP office with the required documents
FYI
You may be required to provide additional documents to confirm Ontario is your primary place of residence if your health card is already expired and/or you have been out of the province for more than 7 months in the last 12-month period.”