This is a case where you need to use the Resuable Scripts Screen, let's start by creating a new Reusable Script. As indicated in this picture, click "Create One" : 


Once you click “create one” you will see the following screen:


Your options now are to:

1) Change the name of the script to something easy for you to remember

2) Edit the email, sms and phone messages for this script

3) Delete the script when no longer needed

4) Clone the script which will create a new script based on any customization you have done in the script (a nice timesaver!) 

If you clone the script, it will show up in the list of scripts like this:

NOTE: As below, you will now have a dropdown menu when you create an appointment so that you can select the script you want to use!