1. Inorder to replace fix or install your new Lenovo N3SG-US laptop fan and heatsink, you will need to open up your laptop. You can do this by removing the screws from the bottom of the laptop.
2. Once the screws have been removed from the bottom of your laptop, you can now remove the keyboard and plastic bezels from your Lenovo N3SG-US laptop.
3. You will see your Lenovo N3SG-US Fan and Heat Skin exposed.
4. Use a screw drivers and remove the screws from you Lenovo N3SG-US HeatSin Fan.
5. Before reinstalling the new Lenovo N3SG-US Fan onto your laptop, you can clean the Lenovo N3SG-US Fan. To clean your Fan and Heatsink, use a can of air and blow out any dirk from your Lenovo N3SG-US Fan. You can also use a paint brush to clean out the dirt from the hard to get areas. Somtimes cleaning your Lenovo N3SG-US laptop fan will actually repair it. Dirt can cause the Lenovo N3SG-US Laptop Fan to make noise and even stop spinning properly.