cr0n0s
The server is the console.
If you are sitting at the keyboard attached directly to your server, then log in as the user root, with the root/admin password.
Then type those commands, very carefully of course.
Type exit (& press Enter) when finished, this will log you out.
If you have never done this before I would be extremely careful and make sure of what you are typing in, BEFORE you type it in.
You can also gain command line access to your server from a Windows or similar workstation or from remote locations using the Putty ssh program. You will need to enable remote access in the server manager first.
I strongly suggest you read the manual, linked at the top of these forums, and search google for a Linux basic commands tutorial, and read it.