It's acctually easy. Go to the computer, click it and select move. Wait until a new window
opens. On the right, select a house or lot where you want to move and check the place
where it says 'make active household' or something like it. Then OK and woilaa he/she will
leave and you can continue playing in the new house. Hope it helped ya.
NOTE!WHEN YOU MOVE OUT OF A FAMILY OF 2 AND MORE YOU CAN'T PLAY THE HOUSEHOLD THAT DOESN'T
MOVE. YOU CAN ONLY VISIT THEM AND INVITE THEM OVER ETC.

you can play the person that doesnt move just go to edit town and click change active
household its pretty ovious from there

i just click on the family's house click split up household and move all of them to the
other side and they then move out