Quote Originally Posted by Eul View Post
Search each folder's log that has your character name on it. Then it contains your character's HUD

Copy the ADDON.DAT and HOTBAR.DAT to your alt's folder.

Source: Reddit.
This thread might be taken down now. When people first started advertising this method on the official forums, all the threads disappeared almost overnight. SE has a hard stance against telling people to go into the game folders and mess with the DAT files directly instead of through the built-in backup.