You need three things: a computer (Mac or PC), a MIDI interface, and a SysEx librarian tool.

A typical Korg SysEx message starts with the standard header: F0 42 3x 28...

The reverse process is just as easy, but timing is crucial.

Open your librarian software, load the .syx file, and hit "Send." The X3 screen should indicate it is receiving data. Troubleshooting & Factory Resets