icloud activation lock

If he has forgotten his password - If you forgot your Apple ID password - Apple Support. If that doesn't help, he will need to consider placing the account in recovery - Recover your Apple ID when you can’t reset your password - Apple Support.

Activation Lock is a theft deterrent, and it wouldn’t be a deterrent if it were easily bypassed.

We can’t tell this case from a lost or stolen iPhone.

And nobody here can release the lock—that’s only Apple folks, and within their policies.

For this case, either the Apple ID and password holding the lock, or the original purchase receipt and phone and matching ID and a discussion directly with Apple.

The Apple ID can be reset using iCloud, and iCloud used to release the lock remotely.

Here is how to do this remotely, once the Apple ID and password are available:

What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support