I feel like death wearing a disguise;;
You have to download the file, save it into your Downloads folder.
"My Documents/EA Games/The Sims 2/Downloads".
If you don't already have a Downloads folder, just make a new folder and name it 'Downloads'.
{Capitalization required.}
Once you have saved it into your Downloads folder, extract it with WinRar or any other extraction program.
And then, play!
It should work.
If not, you should contact the person or site that you got it from.
Hope I helped and didn't confuse you too much!
-----
Senorita Retro