pfsense and the Trigkey Green G1 mini-computer

I am not a FreeBSD user (yet), but I'm trying to install a pfsense
image onto the SSD of a Trigkey Green G1 mini-computer and haven't
been able to do so yet due to its apparently locked-down Windows OS.

If anyone has been successful using that device as a pfsense router, I
would greatly appreciate any help.

I haven't found much documentation from the manufacturer except a
statement that one can remove the existing SSD and replace
it--apparently it's designed not to be overwritten, so it's worthless
to me if that's true.

Best regards,

-Tom