Hi Elizabeth and welcome,
Changing the address via ANTS is easy enough.
The address change is free of charge if you’ve done less than 4 changes and you will receive a little sticker that needs placing over the current address. (Make sure you don’t hide the titulaire when you stick it on).
If this is your 4th change, it will cost 2.76€ for the postage, because they will send you a new carte grise.
If you are doing it yourself you just need to put in the registration number and your new address.
As the véhicule is in your name, I would advise creating your own account unless your OH is co-titulaire, in which case he can do it from his account.
When you go onto the ANTS site do as follows:
'Modifier l’adresse sur ma carte grise.
Connect to your account,
Scroll down to 'Pour Moi-même
Enter your registration number and the other details requested.
Étape suivant
Full in your new address and click oui for the possession of the carte grise.
Étape suivant
Valider.
You should receive the sticker within 4 to 7 days.
If you get stuck, give me a shout.