With the tip of your finger, press down and rub off any large amounts of thermal compound that remain on the chipset. Do not use finger nails at all so as to not scratch the chip. You may want to use the hair dryer if the compound has become rigid again.
Apply an amount of the isopropyl alcohol to the lint free cloth and then gently rub along the top of the chipset to remove the remaining bits of thermal compound for a clean surface. Do the same to the bottom of the new heatsink as well.
