Q: How can I remove an O365 account

Howdy DineroDetroit,

Thanks for using the Apple Support Communities.

In order to delete an email account from your iPhone, all you need to do is follow the steps outlined below.

1. Remove the affected email account from your device with these steps: 
    
   1. Tap Settings > Mail, Contacts, Calendars.
    
   2. Tap the email account.
    
   3. Tap Delete Account.
    
   4. Add your account again.

Get help with Mail on iPhone, iPad, and iPod touch - Apple Support

Have a good one.