I have a Sony VAIO that's about 3 yrs old, don't know the model number off hand, and I'm not at my machine. But to get mine open, you first have to slide the top of the case towards the back, that will then lift off. From there, one of the sides (the left of mine if you're looking at it from the front) will slide and come off. Getting the other side off was a real pain, but I'm not sure that you need to take both sides off. I also took some of the front pieces of the case off because I was replacing the CDR drive with a DVD writer.
It's a pain to get the entire case off, with no directions anyway.
Hopefully this helps.