Product hierarchy change in COPA

Dear COPA gurus

I have 3 layer of product category and plan to use Product Hierarchy in
material master to display this layer.

During fiscal year, change of product category is often occurred.

Thus, in CO-PA, since Product Hierarchy is one of characteristics,

It seems it has to change.

So, is there any good way to change product hierarchy?

Create negative posting and corrected posting of CO-PA doc manually via
excel upload or something?

Yoshi