Acer Aspire E1-521 Service Manual page 118

Slide the ODD module into the slot.
3.
Attach the screw to secure the ODD module.
4.
Install the battery pack (see
5.
5-19
Figure 5:21. Installing the ODD Module
Figure 5:22. Attaching the ODD Module Screw
Battery Pack Installation on page 5-8).
Service and Maintenance