How to remove Quantity Break Column in Item Sales Price?

While I have no problem adding and updating Quantity Break columns for Items, I can't seem to REMOVE an existing Quantity Break column. When I Map the Qty Price column to remove (via the "Item Pricing" subRecord), it has required fields that won't accept Null. I thought using the "Overwrite Sublists" option would work, but so far I haven't had any luck. When I did try, I received a " please enter the missing Price" message for the Qty Break I was trying to remove. Does anyone have suggestions on what I need to do to remove an existing Qty