1. Talk to everyone you see outside, if you wanna go so far as to talk to people inside you can, but it really doesn't matter.
2. Save, quit, close down the game, move the date up 15 days. Make sure the time is between 11am-4pm
3. Once in the game, run around and see if you can find the villager with thought bubbles. They will be outside. If you cannot find them, or there is a fishing tournament (or sometimes rain, but I have gotten a ping with rain) TT ahead one more day. I've had to do this up to 5 days, but you will get a ping.
4. If it's someone you wanna keep, tell them don't go and repeat steps 1-3. You can move forward 6 days between and talk again. It will work either way (I've had more success with the 6 day jump between)
5. If you want them to move, say bye, TT one day and they will be all boxed up, ready for a new adventure.