There are two ways to do this. The first is to obtain a crack, which is a file that replaces your .exe and allows you to play the game wiithout any cd or DVD. The second way is by downloading an ISO file, wihch is a vitual image of the cd. To use it you mount it using a program (Ultraiso, Deamon Tools,etc) and it acts like if the cd/drive was on the drive.
Here is he link to an iso
http://www.taringa.net/posts/juegos/5225708/Sims-2-Teen-Style-Full-_-10-links-_---Megaupload.html
Here isa link ot a crack
http://www.torrentreactor.net/torrents/1385924/Sims-2-Teen-Style-Stuff-Crack-tested!
or
http://www.keygenguru.com/serial/the_sims_2_teen_style_stuff_1.html
To use the crack, copy the downloaded file to where you insstalled the game first driver (C: or D:), then program files or the name of that folder in your case, then EA Games. Inside there you choose the sim game in this case Sims 2 Teen Style Stuff and in there there is a folder named TSBin, there is where you copy the file
The link to that place would be C:/prorgram files/EA Games/The Sims 2 Teen Style Stuff/TSBin
To use the ISO you need to download the ISO file (it is downloaded by parts then put tougether utomaticly when you unzip or winrar the first of the parts). Then using a program such as Deamon Tools, Ultra Iso, etc, you open it and somewhere the option mount will appear, you clikc on that and there will be an option to choose the file, you choose the ISO file and click open and it should mount it. The ISO file contians all the game inside it as if it was the real CD so you will be ableto install it if you need to or play it
hope it helps