You can initiate an editing sequence of a calendar item from a folder list in the Mailbox view or from an entry in the Calendar view. When the item opens, you will be able to change any of the fields or options that were modifiable as a new item.
List editing options: To edit a calendar item from a Mailbox list, such as Sent Items or the Tasklist, do one of the following:
Right-click the item in the list and select Edit from the context menu.
Select the item in the list and choose Edit from the ellipsis menu on the toolbar.
Calendar editing options: To edit a calendar item from the Calendar, do one of the following:
Right-click the item in the Calendar, and select Edit from the context menu.
Click the item in the Calendar to open the item pop-up window, and select Edit from the ellipsis menu on the item toolbar.
If the item was sent to or accepted by other people, they will be notified of any changes to the item by the item being marked unread. If the date and time or the place of the appointment are changed they will have the opportunity to accept the changes.