How can an end user remove a Site Collection Administrator from their OneDrive?
If you are a OneDrive user and notice another person has Direct Access when you go to share a document you can remove them as a Site Collection Administrator by following these steps.
Login to OneDrive on the web
Go into your OneDrive settings by clicking on the cog wheel in the upper right hand corner
Choose OneDrive settings
Choose More Settings on the left
Choose "Site collection administrators"
Remove the users that no longer need or should have site admin access over your OneDrive.
Choose OK