In Amarok, Under the "Tools" menu, select "Script Manager".
Click "Install Script" in the lower left hand corner.
Go to your Downloads directory, and select the file (116823-shoutcast_service_1.0.amarokscript.tar.bz2) that you downloaded. Choose "Open".
Amarok shout ask you to restart. Do it. When you restart Amarok, The Shoutcast service will be installed, but not activated.
Go back to "Tools--->Script Manager" and Select "SHOUTcast Service tralala". Check the box on the left., then click "OK".
You should now be able to select SHOUTcast under "Internet".