.To change a TTS prompt:
1. Login into your Account and Continue
2. From the left hand menu select Services, then Service List.
3. Select the service containing the prompt you wish to change, (if your not sure start at the top and wort your way down)
4. From the Call Flow chart on the service summary page, select the prompt
to change, all prompts are highlighted with the graphic .
5. The Prompt page is the same for vitually all prompts, for a description of the options see message options.
Basically you make suer DO NOT PLAY IS NOT ticked,then change the text in the TTS Script box and then save changes. To listen you can either click the listen link or dial the service number using your phone.