The commands presume you're a site admin with full (including root) access to your server. If you are, then you use a shell account to login as root, and run the commands.
If you're a reseller or a domain owner, then only your hosting company can set this up for you.
If you're a siteadmin and do not feel comfortable running shell commands as root, then perhaps you could contract with someone to do it for you.
Jeff