Step 1
Open Launchpad (Depending on your MacOS version it will look like one of these)
Step 2
Click Outlook
Step 3
Click Outlook, then Preferences
Step 4
Click Accounts
Step 5 - If you have no Email Accounts set up please skip to Step 7
Select your Account and click the Minus (-) icon to delete your account
Step 6
Click Delete to confirm deletion of your account
This process can take a while depending on your mailbox size you will see this message please wait until it disappears
Step 7
Click the Plus (+) and New Account...
Step 8
Enter your Email Address and click Continue
Step 9
Enter your Email Address Password and click Sign in
Allow Outlook to connect to your Office 365 mailbox, this may take a few minutes
Step 10
Click Done to complete your account setup
Step 11
Your Email, Calendar and Contacts will now start to download, this process can take anything from a few minutes to several hours to complete, you can still use your mailbox whilst this is updating