KOBO device - how do I remove the email address associated to my authorization when using ADE?

I have a KOBO aura. I changed service providers and the device uses Adobe Digital Editions to download books.

I want to upload some new books but the email associated to the notifications is the old email address and when I want to de-authorize that email address I am prompted for a password that I no longer remember.

Short of totally deleting my profile and starting from scratch, and losing what I have loaded on the device, is there any way to make this happen to just insert a new email?

Help - since no one seems to have a contact phone number anywhere [either at Adobe or KOBO] and everything is done by users helping users.