The two halves of the core now pull apart (there are no clips, they're held together by friction). The half on the left of this photo contains the main drive (a standard 2.5" SATA 60GB SSD for this model, but others have standard 500GB, 1TB or 2TB 2.5" SATA drives).
The right-hand side half shows the main motherboard under the fan/heatsink assembly.