“a2ensite sitename” – will create the symlink for you
“a2dissite sitename” – will remove the symlink for you
“a2enmod modulename” – will create the symlink for you
“a2dismod modulename” – will remove the symlink for you

When the symlink is place the module or site will be loaded and vice versa.

Do not forget that you still need to reload the configurations into Apache by running “/etc/init.d/apache2 reload”.