How to unlock an iPhone: How to know if the unlock was successful

Once your phone has been unlocked you will receive a confirmation on the phone unlocking from the carrier. Now follow these steps:

1. Power down the phone. Hold down the Sleep/Wake button and move your finger across.
2. Use the SIM card tool (or a straightened paper clip) to eject the SIM card holder from the side of the phone.
3. Remove the old SIM card from the SIM card holder. Place your new SIM card into the SIM card holder.
4. Reinsert the SIM card holder into the iPhone.