You can turn off Find my iPhone by logging in to icloud.com from your computer if your iPad is offline (not connected to the Internet).
If it's online, first turn off the iPad completely (press and hold the power button until the slide to power off prompt appears, then tap and slide on the prompt to power it off).
To turn off Find my iPhone on your iPad, follow these steps on the Apple support page iCloud: Remove your device:
Remove your device from Find My iPhone
Sign in to icloud.com/#find with your Apple ID (the one you use with iCloud).
If you’re already using an iCloud web app, click the app’s name to switch apps.Click All Devices, select the offline device, then click Delete .
The Delete icon appears only after Find My iPhone has tried and failed to connect to your device (this may take a few minutes).
Note: You can also click “Remove from Find My iPhone” in the device’s Info window.
- Click Remove.