1. Loose the screw from the left-hand side of the computer.
2. Slide the plastic part left to release it from the body and then lift it up. On this stage one can clean pretty much most of the dust from the main fan that is easily accessible. To reach the second one, unscrew the screw marked on the figure and proceed to step 3 to lift the keyboard.
3. One more screw and you can release the keyboard (you don't need to disconnect it), lift it and you will have full access to the fans. .Here I have found better guide for PCG-GRT100 that goes to extreme to remove the fans from the main board. It is a perfect illustration how to disassemble each part, step by step, so one can decide to what extreme to go.
P.S. On the pictures above the computer is really in working state. The purpose was to convince the readers that the whole procedure is not difficult at all as long as you have some basic technical skills and confidence. Don't try to experiment like this the first time you open your notebook. The proper (and safe) way is to remove the battery before you open the computer. I keep doing it my way, because I think it works better to clean the dust. Once the dust is blown by the spray it is sucked and blown away by the fans, so at that point I will just advice you to be careful!
