SSH to server
mkdir /root/download
cd /root/download
wget https://download.configserver.com/cmq.tgz
tar -xzf cmq.tgz
cd cmq/
sh install.sh
Login to WHM and scroll to the bottom of the left hand menu and you should see "ConfigServer Mail Queues"
If you want to uninstall, simply:
rm -fv /usr/local/cpanel/whostmgr/docroot/cgi/addon_cmq.cgi
rm -fv /usr/local/cpanel/whostmgr/docroot/cgi/cmqversion.txt
rm -Rfv /usr/local/cpanel/whostmgr/docroot/cgi/cmq/