Lenovo 14M868 Hardware Maintenance Manual page 43

Figure 16. Remove two screws and then remove the system board
Screw specifications
M2 × L3.5
Step 3. Remove the thermal pad.
Figure 17. Remove the thermal pad
Go to
https://support.lenovo.com/partslookup
replacement parts:
System board
Thermal pad
Number of screws
2
to look up the Lenovo part numbers of the following
.
Chapter 4 Removing a FRU or CRU
37