67-9 cuda door repair questions

Ok so got 67 door stripped down, welded up 67 door hole and drilled for 69.
I'll finish grinding the weld up later. Not the greatest but I can work on that later.
Now I'm stripping the 69 door and cant get the blue "plastic rivet" that holds the lift bracket to the door glass. I can get the inner piece to turn but not easily. Is the center piece supposed to be driven out towards door skin a bit?
Thanks
Steve

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