HP A3550A - High Availability Disk Arrays Model 20 Storage Enclosure User Manual page 343

Edge of SP board
2ND PAIR
connectors
Memory modules in
1ST PAIR connectors
Figure 7-11 SIMM Locations
A. Push out on the locking tabs with your thumbs and push
the module up until it is released from the tabs.
B. Lift the module out of the connector and place it in its own
anti-static packaging.
Figure 7-12 SIMM Removal
Locking tabs
Notch
Pin 1
SIMM Removal and Replacement 7-19