You will need to unzip the logo files into the logo directory contained under the appropriate skin folder in your Baseball Mogul 2008 folder. The skins folder is usually located at:

C:\Program Files\Sports Mogul\Baseball Mogul 2008\

If you are using the default skin that comes with the game, click into the skins folder and then into the SportsMogul folder. Within the SportsMogul folder should be a Logos folder. Unzip the logos into this directory.