You can change the business object to which a stored document is already linked, by assigning it to a new business object and deleting the old link.
Procedure
Reassign. The initial object is the business object to which the stored document is still assigned.
The target object is the business object to which the stored document is to be assigned.
A dialog box is displayed.
The target object is displayed for you to check. Once it has been confirmed, the appropriate link entry is created.