Their are a few good PS3 disassembly tutorials on the web. An easy search for PS3 disassembly will provide a few links. However, here is some information I would have liked to know before my disassembly project:
1) The types of screw drivers:
* the security screw holding the "Playstation 3" top cover was a T10 torx sided screw. The star drive shaped screwdriver head should have a hole in the screwdriver head. Think of a 6-sided star shape with a circle/hole in the middle. Recommend a dedicated screwdriver. A screw head from a multipurpose screwdriver may not fit. This is true for some of the other screws below too.
* a few PH1 Phillips size 1 screws
* numerous PH2 Phillips size 2 screws
* bring a couple of flathead screwdrivers (including a very small one) for assisting removing ribbon cables etc.
2) do not forget the top cover "slides left" to open (if your looking towards the system from the front.) After you remove the cover, their is a small metal piece (that holds the security screw) that can go flying. Note how it is positioned on the cover and remove. [see attachment]
3) most of the ribbon cable header assemblies are easy to manage. Be careful with the Blueray disc player main ribbon cable. This assembly has a latching mechanism on each side that can break under pressure. Take extra time with this one.
4) many interlocking pieces in this disassembly. Before removing, move it in/out of place a few times to familiarize yourself with its connection with other pieces nearby.
5) take pictures. This was useful for capturing ribbon cable orientations, etc. [example, see attachment]