You connect your stereo to your computer,mate ;-)
There are lots and lots of threads here about that, do a search - - but in a nutshell, connect a cable from your headphone socket on your stereo to the line-in on your sound card.
WPA2 hack: How secure is your Wi-Fi?
Add Depth Of Field to a photo using Tilt Shift Blur in Photoshop
iPhone tips & tricks
Comment afficher des fichiers cachés sur Mac ?