Need to use the Intel Platform Flash Tool Lite.
https://01.org/android-ia/downloads/intel-platform-flash-tool-lite
Make sure you install the Intel Android USB Drivers.
You run the Flash tool on a PC with the tablet connected via USB. Browse for the downloaded firmware file and select it with the tool. Then just flash it by pressing the button.
Android has Google Play but there is no way to get back to Windows. Not sure if it was wiped out with the firmware update.