Moving sims 'out' with a household greater than 8

Ouch.  I think you need to shift-click remove from household, then go to manage households and put them all into the same household there (they'll be "not in world").  I've never done it, so save first! maybe even save as first.

Edited to add:  If you wanted to move them out with money, you should probably make a note of how much and manually cheat money into the new (uni student) household and out of the original household.