5) Carefully remove the heatsink, completely clean off all the old thermal grease from the top of the CPU and the heatsink and replace with Artic Silver thermal compound. Use a dab about the size of a small pea. Some systems will use a silicon pad on the GPU, this should not be removed and thermal grease should not be applied there.
Recommendations #4 and #5 apply to systems that are outside of warranty. For in warranty systems, please contact Lenovo support for service after confirming the power manager software is installed and working.