I just copy update.img to the root of my USB drive. The USB stick is full of other files (does not have to be blank). If I am in a hurry I hold my on/off button for about 10 sec until I here 2 or 3 beeps and the unit goes into recovery. I select the upgrade from USB. But after the update is completed you need to delete update.img or remove the USB stick as it keeps finding it and prompting me that a update is available.