If you don't have this specific machine, not to worry. Just use some common sense as the basic idea is the same.
Step 1: Tools and Supplies and First Step
Q tips and a screw driver
First Remove your battery (possibly a duh! step, but just being thorough).
Unscrew the Ram cover - to make removing the rest of the case easier.
You'll need to remove the plastic cover just behind the battery 'cave' - remove any required screws and keep track of where they came from (some of mine were longer than average).
Step 2: Removing Fan Ducts/covers
Now we have the lovely task of removing some tiny screws that hold down those two fan ducts/covers. I used a #1 screw driver with a magnetic tip. This saved my butt as I would have easily dropped/lost one of those screws.
Step 3: Clean
When you're done, reassemble.