how do I unassociate a deactivated email account from purchased iTunes

When I purchased songs from iTunes a few years ago, I had an email account with the internet provider in my area but since then have moved away and the email account was deactived.

Now I'm unable to authorize a song to play on my MAC and when I try to reset the password, it sends an authroize email to my old discontinued email account.

Does anyone know how to correct this situation so I don't have to re-purchase these songs a second time? Logically, it seems pretty simple, just change the email to the new one but I can't figure out how to do that to these 100s of tunes. jr