Important: Ensure processor and heatsink bonding surfaces are free from previously applied thermal interface material, oil, dust, and any other debris.
Do not add new thermal grease on top of the existing of old grease. TIM is not reusable and previous Thermal Interface Material should be completely removed.
Do not place a sticker or any other material on top of the processor Integrated Heat Spreader (IHS). Only Thermal Interface Material (TIM) should be used between the processor IHS and the heat sink. Using any other material will degrade the thermal transfer characteristics and could potentially damage the processor (causing the warranty to be voided).
Never touch the thermal interface material as any foreign substances (such as oils from your skin, or chemicals) can reduce the effectiveness of the thermal contact. Thermal grease is very prone to smudging and must not be touched.