Clearing all contributions from an ASIN

Hi.

Anyone can help on how to delete/ clear a listing from catalogue using a flat file. Support is useless and I am clueless.

I downloaded the Inventory Loader File , but there is no DELETE column or something similar, just an OPERATION TYPE column that could be the one.

After some research on their forum, if you add you SKU and and ,x" next to this delete or whatever column, Amazon will clear all the contributions to that special ASIN / listing as well.

Can anyone help with a clear guide on how to?

Thank you very much.