It will take several minutes to complete this task.
You can open your iPhone 3G at home with a couple of simple tools. Especially the first time, work slowly and carefully so you don't break anything. Opening any Apple product on your own can void your warranty, so read the details of your agreement before you begin.
Instructions
1. Unfold a paper clip and use one end to pry up your SIM card from the top of your iPhone.
2. Unscrew the two small screws to the side of the dock on the bottom of the iPhone. Set them aside and don't lose them.
3. Insert the tip of the exacto knife directly above one of the screw holes and begin applying a slight amount of pressure to pry up the glass top.
4. Wiggle slightly up and down to loosen the upper panel from the lower panel. Once it's released on the bottom, grab both sides of the dock end and lift up slowly. It lifts like a panel --- be careful not to pull the top end off completely or disconnect the ribbons at the top end.
Tags: your iPhone