Apple PC Compatibility Card 7-inch card - Manual (Page 146)

Installing the new DIMM
1 Remove the new DIMM from its static-proof bag.
Handle the DIMM by its edges. Avoid touching the connectors.
You may want to put the old DIMM in the static-proof bag until you want to
use it again.
2 Make sure the DIMM lever is in the open position.
If not, gently push the DIMM lever until it snaps open.
137 Adding Memory to a PC Compatibility Card