Basically, just copy the VMT and VTF files to this folder:
Valve\SteamApps\YOUR STEAM ACCT NAME\counter-strike source\cstrike\materials\VGUI\logos
Then start your CS:Source. Go to OPTIONS and scroll down on your SPRAYPAINT IMAGE section to slect it. Then click on OK or APPLY. That's it.....go spray.....have fun.