Not officially. It would have been best just to keep the old account and not set up a new one.
Unofficially;
- deauthorize ADE (crtl-shift-D, or cmd-shift.D on Mac),
- reauthorize with your old ID
- run epubee to strip the DRM on the books registered with the old ID
- deauthorize ADE (crtl-shift-D, or cmd-shift.D on Mac),
- reauthorize with your new ID
