It doesn't matter which interceptor you use, however, I would recommend the - Advanced Packet Editor. WPE Pro is really old, whereas this software fairly new and more stable. It has more features and a better UI.
Just inject it to whichever program you use to access the game and feel free to analyze the packets. But the most important thing is the method itself. With some experimenting, I belive you can do it. If whatever exploit they are using actually works currently.