Steps 1 to 3

• Remove the back cover of your Nokia 3100 by pushing the back cover release button and sliding the back cover off.
• Remove the battery.

Steps 4 and 5

• Pull the locking clip of the card holder and open it.

Steps 6 and 7

• Insert the SIM card.
• Close the card holder.

Steps 8 and 9

• Place the battery back to its location
• Reseat the back cover. You may now switch the power on.