"I’ve had laptops for a good few years now, and never really looked back. The portability and masses of space I save outweighs my desire for a desktop PC and separate monitor.
The only thing that annoys me about my current laptop is the noise it kicks out when things start happening. This noise is my laptop cooling fan, which indicates that my laptop is hot. If it’s really loud then it’s too hot, and that’s not a good thing.
After years of dealing with this problem, I’ve learned that there are a few things you can do to silence that cacophony on your desk and hopefully stop your laptop from falling victim to heat exhaustion."
The hardest part will be getting to it, and whether you fix it or replace it you are going to have to do some disassembly. The two main possibilities are (1) some debris is stuck in the fan, or (2) the bearings are shot. I guess you could just give it a blast with canned air and hope it blows out some debris, but it probably won’t do the trick. Once you get the case opened, you should be able to get to it pretty easily, at least with PCs. I’m not so sure about MacBooks. More than likely, it just needs to be replaced, and that is very simple. I posted a link to a short video below, but what you also need is specific instructions on disassembly. You should be able to Google instructions for you laptop. http://www.howcast.com/videos/326120-How-to-Fix-a-Laptop-Fan