To fuzztone,
Sorry for the delayed response.
I simply followed the "README" instructions found on the SD card after the Sunlight download.
Download the Sunlight files to your PC. They are "zipped" so must be extracted. Once extracted, select them all and copy them (Control C) to your clipboard.
Make sure you wipe all existing files from your SD card, then
paste the new files (Control V) onto your blank SD card.
Shut off your DAC using switch on rear. Remove ethernet connection and I2s connector (if used). Insert your SD card (pins facing up, i.e. upside down) containing Sunlight files.
Turn on DAC using switch on rear. The square blue standby button on front panel, left side, will blink during installation then you will see the "intiialization" screen. Once the initializing has ended, the DAC will display it normal operational screen.
Using your remote, reset the DAC volume control to 100 (from the default value of 25).
You should be good to go at this point.
Good luck and happy listening!
Fred