No. To change a sim (let alone a whole family) is major work requiring specialist tools (SimPE) and a clear understanding of the problem that getting it wrong will cause for the stability of your game. If you just want to change their personality, that's simple. Use Merola's Multipainting, or use the boolProp testingCheatsEnabled true (entered at the neighborhood screen) then when you load the family up you will be able to drag their personality and interests bars up and down. Save and exit afterwards and turn the cheat off (boolProp testingCheatsEnabled false) or you will risk getting into trouble.
