you click on a guest, and set his/her name to Guido Fawkes. Then you go to themix Master and you will notice a new tool to use, this is the advanced firework editor!
When I first got RCT3 I fooled around with the Advance Fireworks (AF) and before Soaked!, you could load an exsisting frw and see how it was made. I did this a few times and wrote everything down to get a better understanding on how to create the frw and what did what. Here is a link that I hope may help you: RCTPyro.com.