You could try turning them with pliers. I made a tool to remove them. I found a nut that fits inside the retainer, drilled the center to clear the stud then welded it to a 1/4 drive socket.
i took a 1/4 nut driver and put it to a grinder on each side of the hex ..still works as a 1/4 nut driver so its is easy to find when doing door panels