How to unassign HU from Delivery which was accidantly confirmed Transfer order

Hi,

We are using QM, WM and HU functions activated. The QM Lot is created with the following HU

Lot 1234

HU 1000007354 -> release from QI to Unrestricted Stock

HU 1000007355 -> Still under QI stock

When we release HU1000007354 from the lot, system will create a Outbound delivery order (OBD). We continue to create a TO from the OBD via LT03. During this step the user accidantly pick HU 1000007355 instead. This resulting in TO confirmed and DO is pack with HU 1000007355. We can't delete the assignment of the HU as the system prompt 'Handling Unit has status - cannot be changed'. We also try to use LT01 mvmt 999 to move the HU From interim storage type 922 to another interim storage type 923, it says 'HU 1000007355 has been as to object 01 <DO Number>, no TO Can be created.

How do we undo this mistake?