Insert your fingernail over the white rubber lip along the inner edge of the expansion card.

Pull the card away from the laptop to disconnect it.

This might take some initial force. If you're having trouble, make sure the locking tab is properly unlocked.

Slide the card completely off its rail and remove it.

Repeat for all of the expansion cards.

During reassembly, align the new card on the rail and push it in until it sits evenly with the edge of the laptop.