Hi all,
I wanted to share this in case anyone else was having the same frustrating problem. I had a personal Microsoft account that I had mistakenly signed into on a work PC. To remove it, I followed the steps to go to Settings >> Email & Accounts, then select the account and click "Remove". Well, I got there, and there was no "Remove" button! Only a "Manage" button appeared.
The "Your info" page probably also looks like this
If you are having this problem, look for a text link on the "Your info" page that says something like "Stop signing in to all Microsoft apps automatically". Click on that text.
"Your info" should now say "Local Account" instead of your email
Go back to the "Email & accounts" page and you should now be able to remove the account
Hope this helps someone.