In The Netherlands it's embarrassing. They basically had to beg supermarkets to stop selling cigarettes and then give them a years long transition period.

It could be very easy. Ban the sales of tobacco to everyone born after "YYYY", make cigarettes cost €50 per pack, make smoking when not allowed a €100 fine, deposit all tax from tobacco sales into a national program where people get free "exercise credits" to be redeemed at fitness studios etc.