How to clear overridden pown data?

Summary:

How to clear overridden percentage ownership data from "Consolidation: Manage Ownership"?

Content:

Data is loaded in January as follows:

Scenario, Year, Period, Entity, Parent, Pown, Control, Method

Actual,FY15,Jan,[C_USA].[C_150],[FCCS_Total Geography].[C_USA],80,,

Data is loaded in February as follows:

Scenario, Year, Period, Entity, Parent, Pown, Control, Method

Actual,FY15,Feb,[C_USA].[C_150],[FCCS_Total Geography].[C_USA],90,,

How can you clear "90" in February so that it goes back system-assigned number of "80", without actually re-overriding again as "80"?

Alternatively how do we clear ownership overridden percentages for a specific hierarchy/period?

This is useful in avoiding rework when ownership data gets modified or corrected in January so its doesn't have to be done twice.