To restore a locked or disabled iPad with a forgotten passcode:
1. Disconnect all cables from your device.
2. Turn off your device.
3. Press and hold the Home button. While holding the Home button, connect your device to iTunes. If your device doesn’t turn on automatically, turn it on.
4. Continue holding the Home button until you see the Connect to iTunes screen.
5. iTunes will alert you that it has detected a device in recovery mode.
6. Click OK, then restore the device.
For further information about restoring a device click here.