Item Template Assign - How to Unassign From Existing Template & Assign to New Template

Hi Experts,

We are in 12.1.3 and implementing GST solution to one of our client. We have applied consolidated patches.

I have created new item template and assigned all the items to that new template. I have also assigned reporting code in that particular item attribute.

Can you please guide me how could I unassign some items from existing item template and assign to another newly created template. When I try to find existing assigned Items in the item template assign, system throws no returns.

Please advise.

Thanks & Regards,

Balaji Jeganathan.