Configuration files are typically installed on the GN4 server(s) during GN4 installing. Normally, they are not needed on GN4 clients (workstations) except for reconfiguration purposes.
In order to customize configuration files on your system, you may choose the following approaches:
Edit files on the GN4 server
This supposes that you will access the GN4 server through remote desktop or similar and edit files in TERA\GN4\CONFIG\ subfolders. They will contain the "last good copy" of all files.
You may want to establish a regular backup of TERA\GN4\CONFIG\ content on another server for backup purposes, but you will never edit the files on the backup server.
Edit files on the local workstation through a shared folder on the GN4 server
This supposes that you are able to access a shared folder on the GN4 server edit files in \\<servername>\TERA\GN4\CONFIG\ subfolders. They will contain the "last good copy" of all files.
When done with editing, you should immediately update the backup server folders with the changed content.
This might be not available when you're connecting to the server through Internet.
Edit local copy of files on the local workstation and then sync manually to the GN4 server
This supposes that you have a copy of the server's \TERA\GN4\CONFIG\ subfolders on your workstation, and that you will edit those local files and load them in the database from the local machine. When done with editing, you should immediately update the server folders and the backup server folders with the changed content.
Use SVN software to store and check-out files
This supposes that you keep the configuration files in a SVN repository stored on a safe place with a kind of automatic backup and that you check-out files before editing them. See Using SVN as source control.
See also
Importing Configuration Items in Database
Installing standard configuration files
Edit ServerConfig, Edit ServerCacheConfig, Edit GlobalConfig, Edit EditorialConfig