How to un-assigned the Bulk item from Subinventory Assignment

Summary: Is there any way to update the Sub-inventory assignment on bulk

Content (required): We can update the item assignment to assign the Bulk item through import template and how can we un-assign the items from the sub-inventory.

Version (include the version you are using, if applicable): 21D

Code Snippet (add any code snippets that support your topic, if applicable):