I'm trying to figure out how to remove the stock cooler from my GEforce 6800. It is held in place by two black pegs or push-pins. How do I remove those black pegs? I have been pushing them in, turning them, and yanking at their bottom 'nipples' to no avail. What is the secret? They push in, and at the bottom the little arrow-headed nipple will rise as if it's about to be ejected, but it doesn't come out even when I yank on it. ARR!