Please note that removing your Exchange account will remove all data related to the account from Mail, Contacts, Calendars, Reminders, and Notes. Any data that hasn't been synchronized with Exchange will be lost.
Open System Preferences
Click on Internet Accounts
In cases where more than one Exchange account has been configured, please ensure you've identified the USask account before removing it. If you are unsure of which account to remove, please contact IT support.
Click the minus button and click OK to remove the account