Before you Start you need the right program go here and download it.
http://www.mediafire.com/?92gjvlixtey
Ok now after you have downloaded it open it up.
Click on "open image"
Click on the Chosen picture you wish to be your spray.
Then click on "adjust image" and adjust it to 96 x 96.
Then click on "convert to 256 colors" at the bottom of the half life tag converter.
Now click "save tag", and be sure to save it to your desktop, an save it as a WAD file and rename the file tempdecal.wad.
Now open up your C: drive and do this steps. "program files", "Valve", "Steam", "steam apps", "Your Steam account name", "counter-strike", "cstrike". ok now drag and drop your tempdecal.wad file into cstrike.
Open up counter strike and you're good to go!