Apple Mac Performa 5300CD - Manual (Page 115)

4 Press down on the card until the connector is solidly in place.
Don’t force the card. If you meet resistance, pull the card out and try again.
To see if the card is properly connected, lift it gently. If it resists and stays in
place, it’s connected.
Installing a communication card
1 Remove the plastic access cover from the vertical plate.
2 Remove the communication card from its static-proof bag.
Hold the card by its edges to avoid touching the connectors on the card.
Communication slot
Push the two plastic tabs apart and pull off the
metal retainer so the access cover can come off.
Vertical plate
Metal retainer
105 Installing an Expansion Card