Korg provides a firmware updater tool which does all the magic for you. It requires to turn the Minilogue XD into »Update mode«. Unfortunately, unlike advertised, neither the english nor the german manual provide any hint how to accomplish that.
On youtube I found a video explaining how to do it for the Minilogue – hold the buttons 6 and 8 pressed while powering on the device. Consequently, it’s just buttons 14 and 16 on the Minilogue XD.