Create a bootable linux live usb-stick
start with it
download USBImager and the latest HA OS on it
install usbimager
flash the downloaded HA OS to your internal ZimaBoard drive
from Generic x86-64 - Home Assistant
Create a “live operating system” on a USB device running e.g. Ubuntu (how-to guide). Insert it into your system and boot the live operating system. Then follow from step 2 in “Write the image to your boot medium”.