How to reinstall KFMon?

I guess my Kobo firmware updated and now NickelMenu says "generator error". I found that I need to reinstall KFMon. I checked github page for KFMon and it says before reinstalling I need to uninstall. In "uninstall" section I read "KoboRoot.tgz ... will automate much of this". What should I do with KoboRoot.tgz? put in kobo's root? unpack in kobo's root? unpack on my computer and run something from shell? (I use linux)

And then, for reinstalling KFMon? Should I just unpack the latest KFMon-vx.x.xxxxxxx.zip to kobo's root, and reboot?

Thank you so much
(perhaps that page on github needs some more detailed instructions, or maybe I'm too noob)