Peter, to do what Gaile suggested, as a manager, go to his profile and click on the "Edit" tab. Scroll down to just before the "Enter text" (for the bio) section and on the left side, you will see a field that says "Email Address:". Just enter the email address he uses in this field and then save the profile. He will then be sent an invitation to join Wikitree. Then follow what Gaile said.