One update to the instructions to switch to a CLASSIC version of MS 365 Office - without Copilot AI. You have to get into your current subscription and hit CANCEL. That will bring up options to Switch to MS365 Classic personal (for 1 person) or MS365 Classic family (for multiple people).
However, be advised that the latest sleazy thing Microsoft has done is to say that you won't be switched to the Classic version of MS365 until your current subscription renews. If you just renewed your subscription, you'll have to wait a year before Classic is activated.
So if you pursue this course of action, you'll still need to disable Copilot on your current MS365 Office subscription to get it disabled until you can switch to the Classic software (minus Copilot AI) whenever your current subscription renews.
If this isn't illegal, it should be.