Don't attempt to remove the SD / Memory Card while the device is powered on. Doing so may harm the SIM card and/or the device.
Ensure that the device is powered off.
From the top edge of the device (display facing up), remove the card tray.
Utilize the insertion/removal tool (or a paperclip) to unlock the tray by inserting it into the provided slot (figure 1) then remove the tray (figure 2).
Remove the SD / Memory Card.
From the bottom of the card, carefully lift to remove. To assist, use the opening on the opposite side of the tray to dislodge (using a fingernail or similar tool).
If applicable, refer to Insert SD / Memory Card.
Insert the card tray.
Press in on the tray to lock it into place.
Check out these interactive demos (S9 or S9+) for more info.