13) Remove the Hard Drive Tray
With so little space inside the computer, a removable hard drive tray is more a necessity than a mere convenience. To get it out of the system, just unscrew the two screws shown on the cage's right side, then lift out the tray.

14) Secure the Hard Drive
There are four grommeted holes on the hard drive tray, two on each side, and four extra-long screws to go with them. Insert the hard drive in the tray so its ports aim inside the case, and so the screw holes on the side of it match up with the grommeted openings on the tray itself. Then screw in those four screws until they're secure.

15) Replace the Hard Drive
With the hard drive installed, you can now put the cage back and secure it with the two screws you took out a couple of minutes ago. Notice the orientation of the drive, with the SATA ports visible in its upper corner; this is the proper positioning.

16) Install the Memory
SO-DIMMs don't look quite the same as traditional desktop DIMMs, but the principle of installing them isn't too different. Line up the notch in the memory with the little post in the bay itself, holding the memory at an angle (as shown here). You'll be able to feel when it's properly positioned because it won't move properly in either direction. Then just push down gently on the memory until it clicks into place, and the two metal catches on either side of the SO-DIMM secure it.