You get access to WCS manager CLI via SSH. To open it you can use a Linux-SSH command line client or any other, for instance, Putty.
In production, change the username and the password to secure ones. Please refer to the WCS Manager Settings section to learn how to do this.
Type help in the command line to receive information on commands.
For a detailed description of a command, you can type that command with the -h key or use the man command.