Dell XPS 15 (L521X, Mid 2012) - Manual (Page 54)

Procedure
NOTE: Your computer’s Service Tag is stored under the system badge.
You must enter the Service Tag in the BIOS after you replace the system board.
NOTE: Before disconnecting the cables from the system board, note the location
of the connectors so that you can reconnect them correctly after you replace the
system board.
1 Peel the mylar from the system board.
2 Note the routing of the antenna cables and remove the cables from their
routing guides.
1
3
2
1 mylar 2 routing guides (2)
3 antenna cables (2)
54 | Removing the System Board