Dell Latitude 7280 Owner's Manual page 45

The component you are left with is the palm rest.
3 Replace the palm rest.
4 Install the:
a keyboard
b system board
c display assembly
d speaker
e coin cell battery
f heatsink
g power connector port
h WLAN card
i WWAN card
j PCIe SSD
k memory
l battery
m base cover
5 Follow the procedure in After working inside your computer.
Disassembly and reassembly 45