Check, delete and add item on an ecommerce site (ECWID) ONLY CUT AND COPY

Hi! I have an ecommerce site. After 2 years i need to check all the listed products (about 8000 items) on it. My products are the same of the products that are actually on my dealer website. Unfortunately they changed some codes, remove some products or add other products. In particular: - check if the products on my website are still on the dealer website (i will give you ID and PWD). If not, delete them. - check if on the dealer website there are products that are not on my website. If yes, add them (i wil show you how) on my website. The work is very easy. You have only to make a simple research by code on our website and check if on the dealer website is still there. You can use automatic tool if works properly. More information if you ask me. Thanks.