위험한 내용들을 포함할 수 있지만 어디까지나 내부구조 파악에 대한 학습용으로 정리하고 있음을 미리 알려드립니다.
https://www.techwalla.com/articles/how-to-program-sim-cards
How to Program SIM Cards
Step
Open your computer's web browser. Navigate to the Website for your mobile phoneprovider (see Resources). Click on the "Contact Us" link at the bottom of the Website. Note down the 800 number to contact the company.
Step
Power off your cellular phone. Flip it over so that the back is facing upwards. Push down on the battery cover; slide it towards you to remove it from the phone. Set the battery cover aside. Slide a fingernail underneath the battery. Lift it straight upwards. Pull the battery out of the phone. Set it aside.
Step
Pull the metal SIM card cover off of the SIM card. Pull the SIM card out of the phoneand locate the identity number on the back, which should be between 16 and 19 digits. Write down the SIM card number and then reassemble your phone. Power the phone on.
Step
Use a different phone to call the 800 number for your cellular provider that you noted down earlier. Provide the customer service representative with your name, mobile phone number and account number. Let him know you need to have your SIM card programmed. Give him the SIM card number you wrote down.
Step
Ask the representative if you need to enter in a specific code on the phone for it to receive the OTA update. Enter the code in and wait for the OTA update to arrive. It will show up on your phone as a text message. Open the message and use the phone's arrow keys to highlight the option that is labeled as "accept update." Hit the menu or enter key on your phone to download the update and program the SIM card.