The backups are done. The moment of truth is here. Settings -> SD & phone storage -> Factory data reset -> check "Erase SD card" and click "Reset phone & internal storage". Confirm with "Erase everything".
After a minute or so a "Sorry!" dialog came up about a service running and asked me if I wanted to wait or force close. While I was pondering the conundrum it started to reboot itself. For a while a rather interesting icon of some green arrows in a circle above an image of a droid with light coming out of it appears, but it went away and rebooted before I could get the webcam set up to take a photo.
The next reboot looks normal but is taking longer than usual.
After only 4-5 minutes it asks me which language and then tries to activate itself. It is unable to do so, then I recall I have a network extender, so I unplug it in case activation can't be completed through the extender. Sure enough, now that the extender is off the activation call goes through, I complete activation and the phone reboots. (I have good signal, but I bought a network extender because my last residence had poor signal.)
It asks again for my language, offers a tutorial on use and starts asking questions about settings, eventually getting to Google account and all the features that require all the companies in the world to track me everywhere I go.