Reinstalling firmware

[dae]

I had installed the beta firmware from a few months ago on a G2 and want to revert back to the 20181016 firmware. I can't figure out how to do that. The 'beta' stopped working on the virtual calculator (Win10x64) with a message about being older than 90 days. I was able to reinstall the virtual calculator from 20181016, and now I want to revert the physical G2.

I downloaded the zip file HP_Prime_Calculator_G2_Firmware_20181016.zip from http://ftp.ftp.hp.com/pub/calculators/Prime/Archive/ It has an image file in it, but how do I install it? What next?

I have reinstalled the 2018-10-16 connectivity kit, and it 'sees' the beta G2 when I plug it in, but nothing in the menu seems to work to revert the firmware.