Article: Press and hold your phone's Power button until the Samsung logo appears in the middle of the screen, then release the button. It may take a moment for your phone to display this field. Once you see the "SIM Network unlock PIN" field appear, you can continue. Type the code you retrieved from your carrier or your selected unlock service into the text box in the middle of the screen. It's below the text box. Doing so will prompt your phone to begin attempting to unlock. Once you see "SIM Network unlock successful" appear on-screen, you should be able to begin using your phone like usual, albeit with a different carrier.  If you see an error or your code doesn't work, you'll need to try a different unlock code or contact your selected service for a refund. If you got your code from your carrier and the code didn't work, call them and report the error before attempting to enter any other codes.
What is a summary of what this article is about?
Turn back on your phone. Wait for the SIM unlock field to appear. Enter your phone's unlock code. Tap UNLOCK. Wait for the confirmation message.