Lenovo ThinkBook 13s Gen 4 Hardware Maintenance Manual page 45

Figure 23. Remove four screws and open the hinge
Screw specifications
M2.5 x L5
M2 x L4
Step 5. Disconnect all cables connected to the I/O board.
Number of screws
3
1
.
Chapter 4 Removing a FRU or CRU
39