If you use the defogger, have patience. It may take a few tries.
Also, a 3rd hand helps SO MUCH (For those who don't know, I am speaking of those little gadgets with the weight in the center, 2 alligator clips on a rod, and a magnifying glass often attached). I stuck my CPU into some styrofoam, had the claws grab that, magnifying glass above it, and managed to place the stuff perfectly with straight sewing pin (tried a toothpick but the pin doesn't soak any of the conductive paint, so worked much better. Also hear that little eyeglass repair type screwdrivers work well). Been going at 1GHz for a couple months now.
And if you screw up, nail polish remover. Alcohol doesn't work that well to get it off.