So, to do this you have to get amiibo cards.
I found out how to do this with Fuchsia and Eugene.
So I had 9 villagers and added Fuchsia. I didn't get anything about wanting to get rid of someone. I time traveled to the next day and added Eugene. This time, Wisp told me who I wanted to force out. When I said yes to one of them, they went immediately into boxes. I haven't went to the next day, but I assume that Eugene will have his reserved plot.
So, I can conclude this:
1) Have 9 villagers (see below if you have 10) and talk to Wisp and ask him to move in and add a villager you want into the game.
2) Wait till tomorrow (or time travel) and make sure they have a reserved plot.
3) Talk to Wisp and add another villager. Ask Wisp to move in. Wisp will tell you a random villager you have and ask if you want to move them out. You can hit "No! Someone else!" and I assume he picks another person.
4) Now, the one villager that you picked to leave will now be in boxes!
If you have 10 villagers, I assume that you don't need to do Step 1 & 2.
It's also worth noting that the villagers you add in will be there intill they leave. So don't add any villagers you hate.
I found out how to do this with Fuchsia and Eugene.
So I had 9 villagers and added Fuchsia. I didn't get anything about wanting to get rid of someone. I time traveled to the next day and added Eugene. This time, Wisp told me who I wanted to force out. When I said yes to one of them, they went immediately into boxes. I haven't went to the next day, but I assume that Eugene will have his reserved plot.
So, I can conclude this:
1) Have 9 villagers (see below if you have 10) and talk to Wisp and ask him to move in and add a villager you want into the game.
2) Wait till tomorrow (or time travel) and make sure they have a reserved plot.
3) Talk to Wisp and add another villager. Ask Wisp to move in. Wisp will tell you a random villager you have and ask if you want to move them out. You can hit "No! Someone else!" and I assume he picks another person.
4) Now, the one villager that you picked to leave will now be in boxes!
If you have 10 villagers, I assume that you don't need to do Step 1 & 2.
It's also worth noting that the villagers you add in will be there intill they leave. So don't add any villagers you hate.