I've been trying to get some villagers to move out, but whenever one of them ping's me and I talk to them and don't tell them to stay, they just change their mind and say they're staying. 
Am I doing it wrong? Is there a way to make sure they go for certain? Do I just not talk to them when they ping me?

Am I doing it wrong? Is there a way to make sure they go for certain? Do I just not talk to them when they ping me?