If you need to remove your email account from Outlook on mobile, please follow the below steps:
- Open the Outlook app on your mobile
- Tap on your profile image and then the settings cog
- Tap on the account to be removed
- Scroll down and all the way at the bottom will be the “Remove Account” option
- Confirm the removal of the account
If you need to setup a different account, you can follow the following process: Office 365 apps on mobile devices