Format your USB stick with a FAT32 file system
Download the USB image of your choice on http://openpli.org/download/vuplus/vusolo2/
Extract the USB image (it is a .zip archive) on your PC using your favorite unzip tool to the root directory of your USB stick. The result is that you get a directory vuplus and in this directory you find a directory solo2 in which you find the necessary files.
Insert the prepared USB stick into the front of your VU+ Solo2 receiver
Switch your VU+ Solo2 off (power-off, not stand-by!). Or choose restart in your receiver: Menu -> Standby / Restart -> Restart and go directly to step 7
Switch your VU+ Solo2 on
After powering on the Solo2 you see: Starting. If the USB-stick is properly recognised you will see the following text (alternating) Update! Press Volume-
During the showing of the above text press the power button (on the receiver!) The text will be shown about 5-8 seconds.
After the flash procedure the Solo2 will be rebooted automatically. If not switch the power off and on again to reboot.
Please bear in mind: To flash an image there may be only one USB-device connected with the receiver and that's the USB-device with the image you want to flash. If there are more USB-devices connected the flash procedure will most likely fail and won't even start!