Go here: [8.2.4.1] LibreELEC Kodi Krypton - S905 & S912 devices
Installation instructions are here: [HOWTO + FAQ] Install community builds on S905/S905D/S905W/S905X/S912 device
Follow the advise:
"I strongly recommend running from SD card/USB drive! Installing to internal memory might soft-brick your box and you will have to reinstall Android firmware to make it work again."
First try with its own dtb file. If not work try another dtb for the S905