Module Size: 4GB kit (2GBx2)
Package: 200-pin SODIMM
Feature: DDR2 PC2-5300
Specs: DDR2 PC2-5300 • CL=5 • Unbuffered • NON-ECC • DDR2-667 • 1.8V • 256Meg x 64 •
Instructions from Apple (found here)
1.Turn off your computer by choosing the Apple () menu, then Shut Down.
2. Disconnect all cables and the power cord from your computer.
3. Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the LCD display.
4. Hold the sides of the computer and slowly lay the computer face down.
Using a Philips screwdriver, remove the RAM access door in the bottom of your computer.
Apple Instructions – Untuck the tab in the memory compartment. If you are replacing a memory module, gently pull the tab to eject any installed memory module.
Mac Website shows a diagram for the orientation of the RAM. The keyway should be as in this picture – basically with the nick/gap to the top left before you insert it. Both slots are the same i.e. the RAM is inserted in the same direction for each slot.
[In the previous picture to the one above (Tabs that hold in the RAM) – to the left of each slot you can just about see the corresponding piece where the RAM slots in.]
Just re-insert the tabs and screw the door back on. After I started up the Mac I double checked in System Profiler and all was OK. It was showing 4GB of RAM (very first picture). Hoorah!