Instructions
Install the expansion that includes the new city or neighborhood you wish to have the family move into. Additional neighborhoods are available on the "Livin' Large" expansion or the "Deluxe" edition of "The Sims." Magic Town, the only other city in "The Sims" where families may actually live, is included in the "Makin' Magic" pack.
Move the family out of their current house. Go to the neighborhood view while in game and click the bulldozer icon in the bar at the top of the screen. Use the bulldozer cursor to select the house belonging to the family you wish to relocate. With the bulldozer pointing to the house click on the "Click to evict this family" message.
Go to the family bin by selecting the "Create a Family" button from the bar on the neighborhood view.
Select the family from the family bin and place them in an unoccupied lot or vacant house in the new neighborhood or town you want to move then into. In the case of Magic Town, make sure the family has enough MagiCoins to needed to purchase the lot (typically between 1,000 and 1,500 MagiCoins).