rename the file SIS506_62.bin to SIS506_sos.bin
and copy only this file on an empty usb stick fat32 formatted
(the file SIS506_62_MD5.txt isn't necessary)
insert the usb stick in the tv, then plug the power cord
look at the standby led, at the beginning it flashes slowly, after about 1 minute it doubles the speed, update completed
unplug the power cord, and then the usb stick
reconnect the power cord and turn on the tv: it starts in first installation mode
if it doesn't work with usb recovery, you have to replace the spiflash with a new one and program it with the file SIS506_sos.bin