How do you open an eMachines M5313 notebook without breaking it?

I have an eMachines M5313, 2 years old and running hot, probably because there must be a lot of dust and crud in the fan enclosure. I have had it shut down on me while surfing the web, though usually it is during a game.

The problem is that laptops are a closed mystery world for no reason at all. This laptop is out of warranty but I only get a runaround from eMachines personnel on this subject, i.e. they will NOT tell me how to open the laptop.

If any of you have the technical maintenance manual for this machine or the M5000 series, send me a note on where I can get the .pdf of the manual.

This would be an immense help for me and would prolong the life of my laptop.

Thanks.

bart.