On your phone's home screen, select: Settings > Mail > Accounts
Select your Olin email account
At the bottom of the screen, press Delete Account
You will see a confirmation page. If you are sure you wish to delete your Olin email from your phone, select Delete from My iPhone. Otherwise, press Cancel.
After a few moments, your account will be deleted.
If you were deleting your Olin email to reset your phone configuration, you can now continue to Add Olin Email to your iPhone/iPad/iOS Device (link coming soon)