Unassign HU from Outbound Delivery with WS_DELIVERY_UPDATE_2 ?

Hi all,

I want to unassign an HU from my delivery and remove the item line which is related to this HU.

I've a structure like below as an example. One HU is packed into another. I want to unassign lower one. After that if upper level HU lefts empty, I want to unassign it also.

I tried to use WS_DELIVERY_UPDATE_2 but couldn't find solution. Which tables should I pass to BAPI? I tried IT_REPACK, VERKO_TAB and VERPO_TAB but no success.

If anyone has done this before or has experience about this process, waiting for comments.

Thanks in advance...