Ok, got the 7800 open but I'm not sure exactly how to get the housing off without breaking anything. I took a pic of the button with my webcam if someone would be kind enough to draw on it to show me what to do.
It looks like the 4 dots hold the plastic down which sounds a little different than it was described although I always do a lot better with pictures anyway.
I'm just afraid I'll mess up something next to the button.