tech support

Hello good people! I'm looking for help on finishing the installation of some headlights that I'm in the process of installing on my 2005 TJ. I have been able to successfully install the lights, and power the day time running lights. However, I have yet to install the Amber Turn Signals...

Theres this big ol dang metal disc on the outside of my output shaft, past the dreaded dust cover. Not sure what it is or what the name is, but can't get the dang thing off. Before I cause substantial damage trying to get this thing off, does anybody have a clue how to... or even what its...