1. Download and install WinRar
2. Download the flex skin file to your PC (desktop is easiest but it can be saved anywhere)
3. Find the downloaded file and double-click it, this should start WinRar and open the file
4. If you see a pop-up window asking you to register, just click the 'close' button
5. Click the button 'Extract To'
6. Select the path:
C

Documents and Settings\{user}\My Documents\Sports Interactive\Football Manager 2008\skins
7. Click OK
The compressed files will be extracted into your skins folder within sub-folders called flex and flex_right