Lenovo IdeaPad 1 Series Hardware Maintenance Manual page 54

Figure 34. Disconnect the battery pack cable and remove six screws
Screw specifications
M2 x L4
M2.5 x L4.5
Step 2.
Rotate the upper case to a degree less than 90º and remove the upper case.
Figure 35. Remove the upper case
Go to
https://support.lenovo.com/partslookup
replacement part:
Upper case
48
IdeaPad Series 1 Hardware Maintenance Manual
Number of screws
1
5
to look up the Lenovo part numbers of the following