Once you have a mover
IF THE MOVER IS WANTED TO LEAVE:
DO NOT talk to the mover, and if they ping you, walk away. Ignore them, and TT 7 days. This will always either be the day they’re in boxes, or their house will already be gone, because the game only gives them a 7-day-or-less period for moving once the mover is chosen.
--- IF YOU NEED SPACE FOR A DREAMY/ WANT TO RESET FOR A DREAMY
If this brings you down to 8 villagers, DO NOT TT any farther, or you risk getting another unwanted villager. Either pick up a dreamy from a friend or cycler, or use the 3DS clock to TT and reset for plots until you get a desired villager.