You'll see that during a reservation and on your summary pages, that there is a side bar with icons displayed on the right hand side of your screen, this is your Case Tools menu. Simply click on an icon to open up the full menu.
Document Store is where you'll be able to view and download all files added during the purchase. This will be split out by type but you also have the ability to download them all in bulk too by clicking 'Download all'. You can also use the 'Shared store' to add files for the buyer to view and download. The buyer can also add files from their end also.