remove itunes account from deceased owner
I recently inherited a ipad. The contents have been erased, but the ipad is still linked to my deceased Grandad's Apple ID. The instructions for accessing the device:
Find My iPhone Activation Lock: Removing a device from a previous owner’s account - Apple Support
all involve contacting the previous owner, which is clearly no longer possible.
How can I unlink the ipad from my Grandad's account?
iPad 2, iOS 8.3