Take the file from the hardware Github release and send it to the manufacturer of your choice. We used Elecrow. The displays were independently sourced from Ronboe and the LEDs were sourced from Shenzhen LED Color Co.,LTD.

Grab the file from the firmware Github release or compile it yourself. 

Hold the up button on the D-Pad and plug the board into your computer using a USB-C cable.

Flash it with esptool or the included Python flashing GUI.