Look at the top of your device, you will see a pin hole. Using a needle, press the button inside the hole and the sim will come out easily. Look on the back of the device and push the small black cover off. If the cover won't slide off, you may need to pry it with a knife. If you do this, take care not to scratch the finish or cut yourself.
 Locate the three pegs that secure the antenna in place and gently pull the antenna off.

You will also see ten more screws along the outer frame that hold the front casing to the internal components. Remove them and keep them handy. Then, remove the main board and battery.
On the back of the iPhone, find the three small screws on the circuit board, which is adjacent to the battery. the screws and gently lift the motherboard section to see the cables that connect to it underneath. Remove these cables, being very careful not to damage the wires and cables. Now, the motherboard and battery can be removed together, and the frame piece can be pulled free as well.
 To remove the display module completely, you must unlatch three retaining clips along the side of the phone. After that is done, carefully pull the screen from the frame.

The cabling that you disconnected earlier is wound through the frame, and you must work them through very carefully to avoid causing damage the fragile wires or connectors.
 You can try in this way.
Pull out the sim and remove the bottom cover on the back of the phone.
Pull out the internal antenna.
Know that the final part is a little bit more delicate.
Get a replacement display module and put it back together the same way that you took it apart.
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