CPUs create heat when doing simple tasks. Thermal grease is a compound applied to processors to help transfer heat into the heat-sink, which is whisked away by the fan. Over time, thermal grease and thermal pads can break down and need repair. When the thermal grease no longer works, overheating will occur and the processor may be rendered useless. All thermal grease must be removed before new compound can be applied. A processor should never run without the aid of thermal grease. To protect your processor and extend the life of your computer, apply a layer of thermal grease between the processor and heat sink every year.
Remove the sides of the computer case to access the motherboard. Remove any screws or clips that are holding the processor fan to the top of the heat sink. Ground yourself against a piece of metal before touching the CPU. Static discharge can harm many computer components.
Remove the heat-sink from the processor. Heat-sinks have metal or plastic clips that lock them in place over the processor; when the clips are squeezed or raised the heat-sink will come off the CPU. You may have to twist the heat-sink slightly to remove it.
Remove the clips from the CPU. Pry the CPU from its socket using your fingers or a pair of tweezers. Use a gentle lifting motion and be careful not to mark the CPU surface. Never place the processor down on its fins as you risk breaking or bending a pin.
Moisten a T-shirt strip with white spirit and rub over the thermal paste. White spirit will weaken the compounds that hold thermal grease together and help lift it from the CPU surface. If the heat sink and CPU had a thermal pad between them, you may need to completely soak the thermal pad with white spirit to dissolve it.
Rinse the surface of the CPU with isopropyl alcohol and allow it to dry. Isopropyl alcohol will remove any oils from your skin that are left on the CPU.
Repeat these steps to remove thermal grease from the heat-sink. Vacuum out the computer fans to aid in cooling. Insert the processor into the motherboard when completely dry. Apply the new thermal compound using the manufacturer's instructions. Attach the heat-sink to the processor, and attach the processor fan to the heat-sink.
Use isopropyl alcohol to remove thermal grease that hasn't hardened.
Never clean thermal grease with the processor inside the motherboard.