You see that off color spot in the fourth pic? That looks to be where the pin was inserted and then welded in place, thats why the finish looks different. The only way to get that off is to cut it, then unless you have a registered sbr you will have to have another re-attached permanently.
I am a member of the NRA. I also try to take an understanding, helpful, and non condescending approach to educating others about firearms. I find that one of the biggest reasons there are so many f'ed up rumors and bad info in the firearms community is lack of civilized conversation. I just...