To install and activate Softaculous on your dedicated server you need to follow the below given steps but before that you need to make sure that ionCube loader is enabled on the server..
cd /usr/local/cpanel/whostmgr/docroot/cgi
wget -N
Softaculous
chmod 755 addon_softaculous.php
WHM > Plugins/Add-Ons >> Softaculous - Instant Installs
Thats it