As long as he is not logged in or not validated, he will see a "resend validation email" link at the top right.
After he clicks that link, another validation email will be sent to the email address registered to the account.
If he does not get an email this way, tell him to check the spam folder.
If it's not there, the email address he entered when he registered the account is another one.
In that case he would have to use the email recovery:
http://forums.d2jsp.org/recovery.php