Google Shopping Ads

We have had a ads account for a year now running shopping ads. We recently got the website redone so the landing pages, Item ID, product prices, google merchant center have all changed. I have already made a feed file and all the products have been approved by the google merchant center.
I have unlinked the previous merchant center and linked the new merchant center to my google ads account.
Now because all the previous products have been deleted I need to add the new products to my previous campaigns>adgroups.