Once the Merish4 is up-to-date, download this file with your PC (it’s about 150MB).
Then copy the downloaded file on a USB stick to the root (root) folder, preferably with this only file inside it.
Turn off the Merish4, insert the USB stick into the Merish4, and turn it on again.
If the whole procedure has been done correctly, just before displaying the list of songs, a pop-up appears asking you to update the sounds: answer “YES” is the update starts.
Wait approximately 20 minutes.
When the procedure is finished, switch off and on again, removing the key.