I have a 7000+ product csv excel file that contains product info from various(5+) dropshippers. Many of the products have been discontinued and need to be removed from the site. My dropshippers provide current csv excel files. I need to somehow reconcile the information without losing the info in the current csv excel file being used. Project consists of editing the current csv file to delete items no longer available and also creating a second csv file with the items that are not currently on the site and need to be added.