hello Carlos,
You can find
YEM here.
After installing YEM on PC, you will need to import "info file" of your keyboard into YEM -without it, you can't create file that your keyboard can read. Read manual how to get that "info file" from your keyboard (btw. file has .
n27 suffix).
Now you can import actual packs into YEM. Once some pack is imported, you can select which styles and voices from pack you wish to have on your keyboard. Until you're not familiar with all that, it's the best if you chose complete pack. To do that, you click on your keyboard button (on the left side of YEM) and select a pack (pack will get green checkmark). After that you click on button on top/right side of YEM to create "install" file. When you get asked where to save, make sure you chose ".ppi" file (on the bottom where you can rename install pack name.
Once you have MyPack.ppi file, copy it to USB stick and then insert stick into keyboard. On keyboard, press MENU button (on the top/right side of display) and press MENU button again -now you'll see MENU 2 on display. Here you select Expansion Pack button on display and follow the instructions on display.
I suggest you start reading Owner's manual
Bogdan