Game won't let me move sim out of 10 sim household

I'm hoping for some advice on how to fix it. 

I use MCCC to increase my household size and now that one of the kids are a young adult, I want to move them into their own house. I build a house to move into, but I can't figure out how to move them out. I don't have the phone option to move out (if that was a thing at all). Since I have a 10 sim household, the game would make me move more sims than just the one out. I also realized that the game is making it so my (base game) limit for the household is 7 sims instead of 8. I'm aware I might have to move people around to fix, but does it require creating a new household for said sim and then moving into a house? I'm going to move the other kids out into other houses soon so I would like to figure out a method prior. I'm new to the sims so any information is greatly appreciated.