Email Set Up Issue

I have a Bold 9000 that works like a charm.
My problem lies in the second Bold 9000 I got from work. The guy who used it before had his emails configured on the phone. Now he is no longer employed, the phone came to me to have it sorted out and assigned to someone else.

So I tried to get into the Email Set up to remove his email addresses. Problem is that he says he"forgot his username and password". So even though I wiped the phone and installed 5.0.411, I still cannot access the email system because I do not know the username and password.

It is on the Blackberry Internet Service and not Enterprise. I contacted the Service Provider and ran into a dead end. No help at all.

Can anybody help me please?