Reset Microsoft 365 Apps activation state

While this article is superbly appreciated in the end, thank you Matt!!! ... it is unbelievable and unacceptable that Microsoft still subjects your paying customers to this nonsense.  As a very technical consumer and part-time multiple company IT admin with 100s of Windows installs and much much more under my belt over 30 years, after purchasing a great second-hand Thinkpad in March 2020 and refreshing its Windows 10 Pro 64bit to factory clean setup, I then proceeding to have to pull all-nighter just to try to figure this activation thing out.  I guess the previous owner must have had ProPlus corporate licensed or something and even a Windows re-install didn't clear the activation.  Just fricking wow!  Absolutely, unequivocally ridiculous and unacceptable that such licensing activation nonsense exists in the first place.  If I didn't have my experience and stubbornness, I would have had to literally throw this perfectly great computer in the garbage.  Get your product managers and "software engineers" (ha, the term is still ironic and brings shame to the discipline of actual for real *engineering*) to stop anti-customer designs!  Seriously!  Enough is enough, we're 20 years into the 21st century now, time to learn to engineer software systems by now!

Grrrrrrrr ....