it is best to install on a fresh linux install
and yes you can install your self (all of current data will be lost)
back up your sites
Virtuozzo power panel
maintenence
Reinstall VPS
options back your old data to "/old" directory (make sure you have enough quota)
after installation
reinstall yum if running linux from the command line
you may or may not have to do the following depending on what template you are running
remove http
then reinstall cpanel