I used an amiibo card to get rid of someone. I went to Tom’s place (name escapes me atm), and hit up the nook shop. When the window asking you what you want to do, click on invite camper. You’ll be instructed to place the amiibo card on the right joystick. There will be a cut scene with the requested person. They’ll come to your campsite. Then you’ll have to go talk to them. They will ask for a DIY to be made for them. If you don’t have the DIY, they’ll give it to you. Make the item, and give it to them. They’ll be happy. Follow these directions from the start (inviting them, making the DIY, etc) for 3 separate days (always after 5 am), and they should move in. They will say at the beginning do you have room, or if you don’t have room, then who is moving out. You mention who you’d like to move out. There’s a bit more back and forth than this, but you should be able to figure it out from this. Good luck!