Since a recurring appointment is only one item in the calendar with the
recurrences calculated from the start date, deleting the recurrence tells
Outlook to stop calculating the recurrences, so your item will show only one
time.  If you set an end date on the recurrence, Outlook will continue to
calculate the recurrences from the start date to the end date, but if you
have any exceptions between the two dates, Outlook will remove them.  Still,
it's better than seeing only the first item.

export to excel then import - this breaks it into individual appointments.