The key is a firm, even pressure. The edges of the core can chip right off if you rock the hs/f on, or your hand slips sideways. The four pads on top of the chip help to protect it from modest levels of pressure. Just make sure that you put it on straight, and that you don't miss the pads if you have a round or unusually shaped heatsink. A friend of mine flaked off the very edge of his core, but it still works fine. Good thing, too. The processor was his anniversary present.
Tom Mc
Even a fool, when he remains silent, appears wise.