Dell XPS 15 Service Manual page 52

Figure 22. Disconnecting the cables
1 touchpad cable
3 power-adapter port cable
5 fingerprint reader cable (optional)
7 tape
9 tape
7 Remove the four screws (M2x4) that secure the system-board assembly to the palm-rest assembly.
8 Lift the system-board assembly off the palm-rest assembly.
CAUTION: Do not hold the system board on the area of heat transfer and circuitry.
52 Removing the system-board assembly
2 keyboard control-board cable
4 speaker cable
6 tape
8 touch-screen cable (optional)