You need to have the item on one character of your account for this to work.
1. Call a GM, whether by ticket or any other means
2. Stand by a bank, and say you'd like a certain item moved from one character to another. You can give reasons for this to help convince the GM; You could say you were on a raid, and the leader wouldn't let you come on your other character. You could also say that a GM gave you the item for an event but he gave it to the wrong character.
3. The GM at this point will remove the item from your inventory- but you will stealthily place it into the bank right before this happens. Now, just log onto your alt, and the GM will add it to your inventory.
Obviously this works with any item, including BOP epics.