Step 1 - Find the Outlook App on your Phone and open it
Step 2 - click on the circle on the top left corner of the app.
Step 3 - Click on the cog wheel at the bottomĀ
Step 4 - Click on your account
Step 5 - Click "Delete Account" at the bottom
Step 6 - Select "Delete"
Your email is now removed from the Outlook App, you can now follow this guide to re-add your account.