Open the settings app and follow this procedure to remove the old account from your device:
Then, to configure the new account, click below:
Quick Access
Useful External Links
Don't forget to set up more than one MFA authentication method for your Single Sign-On! If your phone is your only method and is lost, replaced or stolen, you could temporarily lose access to your account. Guides here: https://help.it.ox.ac.uk/mfa-setup-and-management
Key thing is to make sure you have a backup MFA method. If you are old enough to still have a landline then registering this is a good idea. https://twitter.com/ITBrasenose/status/1471431860836315137
Need guidance on how to set up multi-factor authentication on a new phone, or if your phone is lost/stolen? @ox_it have you covered with this handy guide: https://help.it.ox.ac.uk/mfa-setting-up-multi-factor-authentication-on-a-new-phone