Installing Ubuntu 14.04 LTS to Wyse Z90D7 Windows Terminal

I recently posted how to update Wyze Z90D7 to latest available Windows firmware. Which is far from usable. Let's see how Ubuntu works on this hardware. Actual flavour I picked is Lubuntu, but hardware support should be same for all.

TL;DR: What a piece of shit this is, don't waste your time just toss it to bin already.

Updating Wyse Z90D7 Windows Terminal from USB stick

I recently found old decommissioned Wyse Z90D7 Windows Terminal. Old BIOS, messed up OS, etc. So exactly how do I update this thing without all those complex management systems and active Wyse support contract?