When and how do we swap old-style driving licences?

If you had one of the old paper licences without an expiry date, there is no need to exchange it (until 2033). The new credit- card style licences last 15 years. They are on a standardised EU format, but
France opted for the longest possible period under EU rules. You are not obliged to change the licence if your appearance has changed (though you can if you wish) or if you have moved house.

Licences only feature the surname, but women who have divorced may change their licence if they want to revert to using their maiden name. Renewal does not require a medical. It is done on application to your prefecture with a short form in duplicate (cerfa no. 14882*01) on which you would tick to renew due to expiration de la durée de validité du titre. Prefectures usually require supporting documents including passport-style photos and photocopies of your passport/ID card and a recent utility bill as proof of address.