Dell XPS 14 (L401X, Late 2010) - Manual (Page 73)

Top Cover 73
18 Replace the memory module(s) (see "Replacing the Memory Module(s)"
on page 17).
19 Replace any blank or card you removed from the Media Card Reader slot.
20 Replace the battery (see "Replacing the Battery" on page 14).
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.