4.2.4 Replacing a memory module
Note: For this procedure, it helps to lay the computer on a flat, stable surface.
To replace a memory module:
1.Remove the computer cover. Refer to “Removing the computer cover”.
2.Locate the memory module connectors. Refer to “Locating components”.
3.Remove the memory module to be replaced by opening the retaining clips as shown.
4.Position the new memory module over the memory connector. Make sure
that the notch 
on the memory module aligns correctly with the connector key 
on the system board. Push the memory module straight down into the connector until the retaining clips close.
5. Reattach the computer cover.