Turn off the computer and unplug it
Remove the CPU cooler
Clean old thermal paste from the CPU and cooler base with isopropyl alcohol and a lint-free cloth
Let both surfaces dry completely
Apply a small amount of thermal paste to the center of the CPU
Reinstall the cooler straight down without spreading the paste manually
Tighten the cooler evenly according to the manufacturer’s instructions
Reconnect any cooler cables
Power on the computer and check temperatures