Lift the battery cover off the device from the slot at the bottom of the handset.
Remove the battery by lifting from the bottom.
To remove the SIM card, carefully slide the SIM card from the SIM slot.
To insert the SIM card, carefully slide the SIM card into the SIM slot with with the angled corner facing the top left.
Place the top of the battery in the compartment, ensuring the gold contacts align with the terminals at the top of the handset, and then press the bottom of the battery into place.
Reattach the battery cover, pressing around the edges to snap into place.
The SIM card has been inserted or removed.