My north bridge chip is running a little hot on a 2009 quad. How can I remove the two black plastic snap rivets on the heatsink? I want to put new TIM on the chip, and it looks like I have to remove the board from the tray and then pinch the rivet from the bottom with a pliers but surely Apple wouldn't make it that hard. I was thinking maybe to press and turn the rivet but don;t know. I have even looking for hours but can't find an answer. I hope someone can help me.