Removing Calendars from Outlook:
Removing a Calendar Outlook
This tutorial covers removing an unwanted Calendar from your email account. While you can have as many calendars as you wish and simply tick or untick them to toggle visibility, you may find that you wish to remove some of them in their entirety. This can be done through the web version of outlook. The steps below will guide you through this.
Step 1) Log onto the education Portal using your school credentials. If you don't know how, check here.
Step 2) Open your email account
Step 3) Go to the calendar screen by clicking the calendar button.(Bottom left, next to the envelope icon.)
Step 4) Right click on the calendar you wish to remove, and select remove.

Step 5) A confirmation box will appear, asking if you're certain you want to delete the calendar, so select yes and the associated calendar will disappear.

By removing the calendar here, it will no longer be visible on any associated devices that are linked to your account such as the outlook app on your phone or PC.
If you wish to add a calendar instead, you should check Install College Calendar to Outlook