uploads are available for pro accounts.

You can upload a price & quantity template and zero out your inventory.

For individual accounts & pro, go to inventory management

https://sellercentral.amazon.com/myinventory/inventory?

check to top left box that says “Listing status” this will select all the listings on your page. A box will popup from the bottom where you can choose close listings.

You can change the number of listing per page to 200 so you can do 200 at a time.