Instructions
Navigate to a download site for the "SMOD Outbreak" modification.
Click on the download link to automatically begin the download.
Open your download folder and and right-click on the downloaded RAR file and select "Extract Files."
Alter the destination folder so that the files extract in "C:\Program Files\Steamapps\Sourcemods."
Restart "Steam" and look for "SMOD Outbreak" in the game list. Click on the icon to launch the game.