I heard using the "pan method" was a lot simpler. use a razor to cut under the ihs all around, then put a razor under each corner. take a baking pan, and put it on a burner, then heat put the cpu ihs down on the pan. heat up the burner, and when the ihs gets hot enough the chip will pop free of the silver. Someone at xtreme systems did it that way.
The sanding method has the advantage of leaving enough of the IHS behind to help support the heatsink.