I read through this entire thread and nothing looked the same as described.
I have a work Surface that was set up with a Microsoft (MS) account. I added a local account and gave it administrator priveleges while logged in with my MS account. I then logged out of the MS account and logged into the local account.
Then you can use the other instructions in this thread to remove your MS account. Hope this helps someone as it took me awhile to figure this out.