A very basic overview of how I cleaned the dust out of my Toshiba laptop's heat sink. There was so much in there! I can't believe this practice isn't recommended and encouraged by the manufacturers.
If dust is blocking the air inlet and outlet and/or the heat sink, your computer may overheat. Symptoms of overheating include very hot air coming out of the outlets, an unusually hot base, or the computer suddenly shutting off for no apparent reason. If your computer doesn't have a low enough setting for automatic shutoff due to overheating, the components inside may be damaged.
I broke no stickers or seals while doing this, but there is a possibility of leaving some marks on screws or covers. This almost certainly voids your warranty, so keep that in mind before you start!
This was a very easy process but can present many opportunities for dropping tiny screws. If you have a tendency to drop things or aren't good with screwdrivers, please hire a professional to do this for you.
Step 1: Remove fan cover
The first picture is obviously the computer base. The fan cover should be easy to identify. I recommend placing a cloth or something down before overturning your computer. I didn't ... oh well.
The three screws circled in red are hex screws. I didn't have a hex driver so I used a small flathead that fit well. Not a great idea, but it worked well enough.