Go to the following folders: My Computer, Local disc (C:), Program Files (x86), Steam, Steamapps, your steam username, Team Fortress 2, tf, materials, VGUI, logos, and drop the provided files in that folder. Once in-game, go to Options, Multiplayer, and the spray should be on the little drop-down list for sprays. If not, click 'browse', and go back to the Logos folder and select the spray.