cultivate a list of websites that have europeans who have accounts
have a single portal where, for a small fee, you will do the heavy lifting of deleting their accounts on those websites.
Expose the user a checklist of sites they have accounts on, with "APPLY" - if you put a checkmark in that website, and hit apply, you will contact that website to delete your account
Way easier than doing it one by one for the user, and there are millions of europeans in market
Welcome to your niu world ! We are a cute and loving international community Ｏ(≧▽≦)Ｏ !