Sony PCG-XG28 Primary User Manual page 53

Remove the PC card slot protector.
When you use a Type III PC card, you need to remove both the top
and bottom PC card slot protectors.
Insert the PC card into the PC card slot with the front label facing up.
Gently push the card into the slot until the card is fixed into the
connector. The RELEASE button comes out. Push down the
RELEASE button toward the display panel.