Need help with Strobe Slipper

I just got my Strobe Slipper and feigao 8xl setup today. I was hoping I could just slap it all in and go, but thats not the case.

I can't seem to get the slipper setup to fit on my stock emaxx input shaft. It appears the bearing used in the slipper is to small to fit around the hex shaped shaft. Is there a way to fix this?? Do I need to use more force?? Help please I am dying to try out my new setup!!