Perform the following steps:
Double-click on the meeting in the schedule pane, to open the Appointment window.
Click on the Meeting tab to display the Meeting tabbed section.
Right-click on the attendee whose invitation you want to revoke,
then choose Delete from the popup menu.
Email and Calendar deletes the attendee from the attendee list.
Repeat this step for each additional attendee whose invitation you want to revoke.
Choose File -> Save and Close.
Email and Calendar asks if you would like to send the updated meeting information.
Click Yes to send the updated meeting information to the specified mail addresses:
A message with the subject Cancel:Calendar Information is sent to the attendees whose invitation is revoked.
A message with the subject Calendar information is sent to the attendees who remain on the attendee list.
Click No to save the updated meeting information without sending a message to the specified mail addresses.