Cooling fans are integral to keep the components inside your laptop from overheating, and a damaged, broken, or insufficient one can means very bad things for your laptop. This guide will show you how to get to it and remove it for inspection or replacement. Most of the steps are fairly simple, but be careful with ribbon connectors and snap-connectors holding down housing plates, breaking those can cause trouble for you down the line.
If your laptop regularly overheats, replacing this component should be something you look into. This guide will also show you how to access and remove your HDD, your DVD drive, and your keyboard if you need access to any of those. Good luck!