Dell Precision M40 - Manual (Page 21)

The system board's BIOS chip contains the system service tag number, which is also visible on a bar-code label on the bottom of the computer.
The replacement kit for the system board assembly includes a diskette or CD that provides a utility for transferring the service tag number to the replacement
system board assembly.
Removing the System Board
1. Follow the instructions in " Preparing to Work Inside the Computer ."
2. Remove the hard drive and the fixed optical drive .
3. Remove any installed Mini PCI Cards .
4. If migrating the memory, remove all installed memory modules .
5. Remove the keyboard.
6. Remove the hinge cover .
7. Remove the display assembly .
8. Remove the palmrest assembly .
9. Remove the video graphics board .
10. Remove the microprocessor thermal cooling assembly .
11. If migrating the microprocessor, remove the microprocessor module .
12. Remove the three 4-mm captive-washer screws from the system board.
13. Remove the 20-mm screw from the center of the LED board.
14. Lift the front of the system board and work it out of the back panel.
System Board
NOTICE: If you received a flash BIOS update program diskette or CD with the replacement microprocessor, you must update the BIOS after replacing
the microprocessor module. For instructions on updating or reflashing the BIOS, see the Dell Portable Computer BIOS Update Guide.