In the zip file you download there should be a file whose name ends with .PCG
That file contains the actual Programs and you need to copy it to an SD card and then put the SD card into your M50. From there you need to go into Disk mode and load the PCG file from the SD card. I don't own an M50, but I've played with enough Korg workstations to know that there is definitely a section in the owners manual called "Loading & Saving Data" or something of that ilk. That will give you the specifics of how to load a PCG file, and whilst you're there be sure to brush up on how you save data (Programs, Songs etc.) back to the SD card. That's an essential skill; so you can backup your sounds and also save the songs you might be working on.