Acer Altos R5250 - Manual (Page 74)

3 System upgrade 56
5 Align the BMC module so that the notch on the slot fits the keyed
edge of the module (A), then press the module at both ends to
snap the snap the standoff into the matching hole on the module
(B).
6 Reinstall the SAS daughter board.
7 Observe the post-installation instructions described on page 28.
A
B