Instruction on how to disassemble the Asus A52J laptop in order to replace the hard-disk.
I uploaded a video on youtube to demonstrate the procedure.

It boils-down to 5 steps:

1. Remove the Battery
2. Unscrew and remove the back-plate
3. Unscrew and remove the hard-disk caddie
4. Remove the hard-disk from the caddie
5. Replace with fresh hard-disk and reverse the procedure.