Click on this link to read about how to deactivate your Apple ID account --> How to deactivate your Apple ID account - Apple Support
- See the section about "Can I reactivate my account?"
Then read what to do before selling or giving away your iPhone, iPad, or iPod touch
What to do before you sell, give away, or trade in your iPhone or iPad - Apple Support
If you cannot reactivate it, Apple can completely reset a device if a person can provide sufficient evidence of valid ownership. Do this online at: Activation Lock support request - https://al-support.apple.com/#/additional-support Apple says, "Proof of ownership documentation is required," but does not detail what currently constitutes proof. Prior to this service being offered officially and moved online, Apple typically required the original receipt issued by Apple or an Apple Authorized Reseller. If Apple resets the device this will give you access to the device but won't restore access to the account used to lock it. There is nothing that can be done to expedite an Activation Lock request.
Apple recommends you "Keep your receipt after you buy an Apple device" --> Keep your receipt after you buy an Apple device - Apple Support