How to replace a unverified email address with a working Apple ID? iPhone 5s

Hi Everyone,

I have a one of our Executive members who has used a email address when he created a AppleID, but he never verified the email address, because He typed in a wrong address, like:

His address is d*****@s****k**.co.za and he typed in d*****@s****k**.com

We don't have the password used.

Now the Executive was suspended for some reason, which I can not disclose, but we want to clean this iPhone 5s, and assign it to the acting Executive, I have been struggling since 7th April 2015, and I am under pressure to resolve this matter, is there any way I could get some Guru advise?