If you previously downloaded Body Shop from the thesims2.ea.com/ website then you might need to clean up your Start menu first. Body Shop will be found under: Start >> ~~ EA Games >> The Sims 2 NOTE: The red ~ in the above line indicates a possible pathway that may exist because you may have moved, or otherwise chose to have, the EA Games folder in a different place within your Start menu either during or after installation. If you cannot find it this way you will find it by using My Computer and going to:- C:\Program Files\EA GAMES\The Sims 2\CSBin\TS2BodyShop.exe ... if your right click the above file and choose Send To >> Desktop(create shortcut) you will place a shortcut on your desktop that will launch Body Shop. Note that Body Shop can take quite a while to load.
So ... you will find it in the way I described. (Note that BodyShop will not start if The Sims is already running.)