If you’d like to rename one of your reminder templates in your account you can! To rename a reminder template, do the following:
Go to Settings > Reminders.
Select the template you want to edit from the dropdown menu in the Reminder Templates section.
In the text box that appears with the current reminder template title, edit and type in the new title of the reminder template that you would prefer.
Click the Save button next to the reminder template name to keep the changes.
Once the steps above are completed, you will be able to find the new reminder template title/name in the Messages drop-down menu on your appointment creation form and in the Instant-book Appointment Messages dropdown menu for your Booking settings.
Here's a screencast showing you the above steps: