Why isn’t the Exchange option showing up?
If you go into an order don’t see the Exchange option under Order Actions. This is not because it is not possible to do an exchange, it just means that the event that ticket is part of is not associated with an Event Group.
In this case, the best way to handle an exchange is to use the Refund to Credit functionality. Simply refund the order in question to credits and then purchase the tickets to the new event using the existing customer file and those credits will automatically handle the purchase.