To add a new template for your AUTOMATED appointment reminders go to the GEAR ICON at the top, right hand side of your account> SHOW TEMPLATES page and click into the Appointment Reminder SMS (there are a few different options, you will want to choose the template you are currently using).
You will then click on the blue COPY button which will create a duplicate Appointment Reminder.
Click on the Appointment Reminder COPY template.
Make the necessary changes to the COPY template and click SAVE.
Now we need to go to GEAR ICON > AUTOMATION page and change the Send SMS Field from Appointment Reminder to Appointment Reminder COPY.