Dell XPS 15 (L502X, Early 2011) - Manual (Page 22)

22 Wireless Mini-Card(s)
4 Disconnect the antenna cables from the Mini-Card(s).
5 Remove the screw that secures the Mini-Card to the system board.
NOTE: Your computer can only support either a WWAN Mini-Card or a TV tuner
module in the full Mini-Card slot at a time.
6 Lift the Mini-Card(s) out of the system-board connector.
1 antenna cables (2) 2 Mini-Card
3 screw 4 system-board connector
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3
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4