Insert the first disc of the DVD set and from the (Main Menu) go to the (Episode Index). There, highlight the menu entry (Menu) and then press the [Right] arrow key on your remote control to highlight a blue figure in the center of the screen. Now press the [Enter] key to see a message by Scott Bakula.
Go to the (Bonus Materials) on disc one and there highlight the menu entry (A Kiss With History). Press the [Right] arrow key on your remote control to highlight the blue figure and then press [Enter] for another message by Scott Bakula.
A third message is hidden in the (Languages) section of the first disc, accessible from the DVD's (Main Menu). There, highlight the menu entry (francais) and then press the [Left] arrow key. This highlights another blue figure and give you access to a message by Dean Stockwell.