Acer Aspire S5-391 Service Manual page 124

Lift to remove the middle cover.
4.
Remove the 10 screws securing the upper case to the lower case.
5.
CAUTION:
A cable is still connected under the upper case, do not abruptly lift the upper case.
Service and Maintenance
Figure 5-22. Removing the Middle Cover (2 of 2)
Figure 5-23. Removing the Upper Case Screws
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