4.Replace the screw that secures the optical drive to the base cover.
5.Replace the memory module(s) (see Replacing the Memory Module(s)).
6.Replace the module cover (see Replacing the Module Cover).
7.Replace the battery (see Replacing the Battery).
CAUTION: Before turning on the computer, replace all screws and ensure that no stray screws remain inside the computer. Failure to do so may result in damage to the computer.