How to add and remove a sim to my household on the same lot? // Switching between sims on one lot

I need help: I need to delete the other half of my family tree because I don't want them to be connected to my family. When I downloaded and extracted the Twallan's master controller (I think it's called that) it wouldn't let me load sims 4 open so that created a new problem. I just want to erase the other half without damaging my family tree and I already saved so it's not like I can just go to the main menu.