Administrators can remove the accounts of other users. When a user is removed, all of their work will remain, and the administrator who removes them will inherit all ownership.
First, head to the Settings Menu.
Once you are in the Settings Menu, click the Permissions tab:
Hovering over a user's name will cause a small gear icon to appear on the right-side of the page.
Clicking this gear icon prompts the admin with actions to take for the user's account. The "Remove" button will prompt the admin with a confirmation to remove the user.
Upon the admin confirming, the user's account will be deleted.