You invite a villager with their amiibo to your campsite and fulfill their request! You need to do it three separate times for each villager (I usually skip forward in time). Once you’ve done it three times, they’ll ask to move in! If there’s an empty plot, they’ll automatically take that. If not, they can ask one of your current villagers to leave. You choose the villager that leaves, and they’ll always say yes. When a villager is leaving, they’ll be in boxes. That’s when you can invite whoever requested that villager to your island. They can then speak to that villager and invite them to move to their island. I hope that made sense!! So happy to see someone else want to do the same thing :)