9.Unplug the speaker cable and remove the Bluetooth module

10.Remove the motherboard screws, remove the clasp of DC Jack, and remove the screws of VGA

11.Lift the motherboard from the left

12.Erase the hardened silicone grease and apply a little of new grease.

13.Follow 1 to 4 of the screws to fix the heat sink. Remember to install the fan's cable

14.Fix the right side of the DC Jack first(the screws of motherboard are the same size, it can be mixed)