Acer B1-720 Service Manual page 77

Align the top side latches on lower case with the top side slots on the bezel.
3.
Snap the top side latches to attach the lower case to the bezel.
4.
Service and Maintenance
Figure 5-12. Aligning the Lower Case with the Bezel
Figure 5-13. Installing the Lower Case (1 of 4)
5-11