ctrl-shift-D to ADE will deauthorise ADE. Restart ADE (maybe not needed) and you can then reauthorise with the correct ID.
You should then be able to authorise the device with that ID.
Warning: you will not longer be able to read DRM books downloaded while you had the 'anonymous' id.
For library books, return them before you make the change, and then borrow them again after the change.