How do i clean inside of my iMac? I want to clean the inside of my iMac. The mac : iMac Mid-2007

How do i clean the dust from inside or clean inside of it. Basically im saying how do I open the mac?
There's an access door on the bottom of the Mac which can be unscrewed.



For further access, you need to take the glass off, which is fixed with fourteen magnets.



Source: http://www.ifixit.com/Guide/iMac+Intel+20-Inch+EMC+2133+and+2210+Hard+Drive+Replacement/1008