EDIT1:
ALWAYS HAVE A BACKUP SAVE BEFORE DOING THIS JUST IN CASE!!!!
Here's a step by step guide since I've just successfully moved 8 villagers of my liking.
1) Save your game and extract save file.
2) Open save file with NHSE and go to Villagers tab and find the Villager you want to replace.
3) Insert empty.nhv inside the ZIP file called "empty.zip" that I've attached. (Thank you
@eskil for this data and info)
4) Save file. Reload that save into your switch and visit your island. The plot should be empty WITHOUT THE SOLD SIGN.
If successful, you can proceed to the next step. If not, you've done something wrong.
5) Time travel 1 day later until SOLD sign appears
OR
Invite someone to move into your house to force SOLD sign to appear.
I personally just time travel but I do believe inviting someone can be a better method.
Once SOLD sign appears. Save and load save file into NHSE.
6) Now go to the Villagers tab and find the villager moving in and replace it with the Villager you want. For this example I will use Kabuki.
Species: 4
Variant: 9
Peronality: Cranky
Catchphrase: meooo-OH
After that, save. load that file into your game. Go back to the plot and make sure your choice of villager's name is on that plot.
Once successful, time travel for them to fully move in and visit their house.
Hope this guide helps. Let me know if you're unsure or want more question regarding this. And if someone wants to re-write this guide into a better format, feel free