This document will walk you through how to share or change your sharing permissions in Office 365 calendar.
In your web browser login to VCSU Office 365: email.vcsu.edu (login with firstname.lastname@example.org).
At the top left corner of the page, select the app launcher , and select Calendar (calendar may be listed under the All apps link).
Under Your calendars, right-click the calendar for which you want to update sharing settings, and select Sharing permissions.
Find the person whose permissions you want to change and either choose a new level of permissions or select Remove to stop sharing your calendar with that person. click on Done to save changes.
NOTE - When you remove a person from the list of people with whom you've shared your calendar, the URL that was sent to that person stops working. If the user is also within your organization, the calendar is removed from their list of calendars.