Essentially, I followed this guide: https://discourse.coreelec.org/t/guide-s922x-j-ugoos-am6b-coreelec-installation-and-faqs/51231

These are my personal notes based on installing four of these, with my hardware being:

…but should prove enough of a guide for anyone else to get going!

First! → Pre-Install Boot to Android Steps

Boot into the Ugoos interface and check the firmware is up to date, update if not. Mine say:

Firmware is 0.5.4n

While in there, also adjust the power settings so the switch (sort of) works as an on/off switch:

Device Preferences → Power Settings → Disable Auto Power On

Pre-Install Steps