You can install Icecast by typing the following command in your SSH console:
/usr/local/centovacast/sbin/update --add icecast
If however the update script skips over the Icecast 2 package, it would mean that Icecast 2 is already installed, and you just need to manually link Centova Cast to your existing binary using the following command.
/usr/local/centovacast/sbin/enable_package ICECAST /usr/local/icecast/bin/icecast
If you see any error message, please send us the complete output, otherwise Icecast should now work as expected.