Change Subinventory and Locator After Auto-Allocation on EAM Work Order

We are in R12.2.4 and using EAM module.We are using Two-Step Material Issue with Auto-Allocation for the material on EAM Work Order. After releasing the Work Order, material gets automatically allocated with Subinventory and Locator. But if user wants to change the Subinventory and Locator, how can he be able to change it. Please suggest the steps or setups required. The EAM Org does not have 'Locator control'.

Secondly, what happens to that allocated quantity (which is auto-allocated thro' particular subinventory and Locator), if we change subinventory / Locator. It should reverse back to place.