Download file to your computer
Save the file on a USB stick. Make sure it is the only file on the USB stick
Turn off the speaker
Press constantly on Connect button
Turn on the loudspeaker (keep pressing the Connect button)
Note, that LEDs light up, moving once in a slow circle (release Connect button)
Insert USB stick
Note, that LEDs light up quickly in a circle
Turn off loudspeaker
Take out USB stick
The speaker is updated.