While editing the order to be rescheduled, on the Inspectors Date and Time tab there is a button labeled Send Reschedule Notice and one for Send Reschedule SMS
Click on Send Reschedule Email and it saves the order you are working (first) and then pops up this screen
If you click on Send Reschedule SMS it will save the order you're working on and then pops up THIS screen:
Select the appropriate template or customize your texts (beware of the 120 character limit in text messages!) and hit the green Send... button!
Note: The popup for sending a reschedule email always remembers who you checked and what template and it restores them next time.