Very basically, you have to extract the content of zip or rar files (those are 2 different types of compressed files) and install the necessary content into the Downloads folder located at My Documents--EA Games--The Sims 2.
If there is no already existing folder named Downloads there, create one - name it exactly as spelled here, including the capital D: Downloads
Do take a look-see at this more comprehensive guide to the basics of downloading and installing content for the game:
http://www.sims2wiki.info/wiki.php?title=Game_Help:Downloading_for_Fracking_GeniusesA couple of things there are out of date or incomplete as there are better alternatives. In short, those are:
If Q-Express is mentioned anywhere in that guide, ignore it. Q-Express is kaput, gone, never to return.
In the bit relating to rar files, ignore the advice about getting and using WinRar. Strongly recommend instead getting and using (it's free and user-friendly) 7-zip:
http://www.7-zip.orgfor unpacking the content from both zip and rar files.
If you still are unsure o have further questions, don't hesitate to ask.
