If you’re no longer using an iPhone, iPad, or iPod touch that was set up to use Find My iPhone, you can remove it from Find My iPhone when the device is offline (turned off or not connected to a data network, such as EDGE, 3G, or Wi-Fi). To remove the device, you need to sign in to me.com on a computer.
To remove your device from Find My iPhone:
On a computer, sign in to MobileMe Find My iPhone at me.com/find using your Apple ID email address and password.
If you’re a paid subscriber, your Apple ID is your MobileMe email address (@me.com or @mac.com) and password.
If you set up Find My iPhone on more than one device, click the device you want to remove in the Devices list on the left.
Click the blue arrow to the right of your device’s name (or, if the device hasn’t been located recently, the red clock ).
In the device window, click Remove (to the right of the device name).
The Remove link appears after Find My iPhone has tried and failed to connect to your device. This may take a few minutes.
When asked to confirm if you want to remove the device, click Remove.
If your device goes online again later and is still set up with your MobileMe account information, the device automatically reappears in Find My iPhone. If you still have access to the device, you can prevent it from reappearing in Find My iPhone by removing your MobileMe account information from the device. Tap Settings > Mail, Contacts, Calendars > YourMobileMeAccount, and then tap Delete Account.