Preramble: I got this very cheap ($79) Windows 10 computer because I'll be travelling and don't want to worry about losing it. For previous travels I developed a script to capture my GPS log and pictures and made a blog page with map from them. That computer is heavy and sickly.

The Ematic EWT8268K has a hobbled UEFI which does not allow booting from an external device (no EFI mount command). The CPU is Intel Atom Z373SG. 1GB RAM The SSD is 32GB and I can put in a 32GB microSD

What is the very manual process for putting Ubuntu on the microSD? I can modify the existing boot manager. There is some incantation to which I am not privy. Can someone help with this challenge?