Dell XPS 13 (L322X, Early 2013) - Manual (Page 30)

Replacing the Heat Sink
NOTE: The original thermal grease can be reused, if the original system board
and heat sink are reinstalled together. If either the system board or the heat sink
is replaced, use the thermal pad provided in the kit to ensure that thermal
conductivity is achieved.
1 Clean the thermal grease from the bottom of the heat sink and reapply it.
2 Align the screw holes on the heat sink with the screw holes on the
system board.
3 In sequential order (indicated on the heat sink), replace the screws that
secure the heat sink to the system board.
Postrequisites
1 Replace the battery. See "Replacing the Battery" on page 18.
2 Replace the power-light board. See "Replacing the Power-Light Board" on
page 16.
3 Replace the base cover. See "Replacing the Base Cover" on page 14.
4 Follow the instructions in "After Working Inside Your Computer" on page 11.
Heat Sink 30