I want to change my main or one of my file servers. What should I do in order to perform that?
1. Set up your destination server and configure all required software just as usual. If you're not sure which software have to be installed, then refer an appropriate section of INSTALL.txt which is bundled with XFileSharingPro core distribution and respective mods.
2. Copy all files from cgi-bin/ and htdocs/ directory to your new server, with preserving paths if possible. If it is not possible to preserve paths, you will have to carefully update XFileConfig.pm and XFSConfig.pm accordingly.
In the case of main server, you will also have to move your MySQL database and MySQL user privileges.
3. Test that your new installation is fine (you may have to add your new server in desktop system's etc/hosts for that), then switch your DNS zones accordingly.