Need Held Disassembling Aftermarket Headlight

Okay so I have purchased this>>>

$169 Spec-D Tuning Black Clear Projector Headlights Compatible with 2005-2011 Toyota Tacoma Left + Right Pair Headlamps Assembly

https://www.amazon.com/gp/product/B01EZYZXQM/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
headlight and so far I've been able to take the housing apart but cannot get this "cap" (im assuming its a cap) off of the back of the headlight. Here are some pics:




It looks like it can just unscrew off but I don't want to force it off and break the headlight. If anyone can tell me how to get this part off and the name of the part that ould be awesome!!

 

Based off pure assumption, I would assume that white cap or whatever it is is epoxy'd/JB welded on there. They probably did this to prevent the projector from moving or tilting to one side or another, and assumed no one would be in there to tinker with it. I think this is pretty standard practice when people retrofit their headlights themselves. But again, I'm assuming all of this.

 

Yeah however it's held on it ain't moving! I think I'm going to leave it be and just around it the best I can. Thanks for responding though Mike