Dell Inspiron 15 (3542, Early 2014) - Manual (Page 74)

Procedure
NOTE: The heat sink may look different on your computer depending
on the configuration you ordered.
1 Turn the system board over and place it on a flat and clean surface.
2 In sequential order (indicated on the heat sink), loosen the captive screws
that secure the heat-sink assembly to the system board.
3 Disconnect the fan cable from the system board.
4 Lift the heat-sink assembly off the system board.
1 fan cable 2 heat-sink assembly
3 captive screws (5)
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