Removing items from your Project or Account
To "Remove" a Product or Keyword and stop tracking it, in your Products or Keywords list, click on the blue drop-down button in the far right side of the item you want to archive, then click on "Remove from Project" and it will remove it for this project only. If you click on "Remove from Account"; it will remove the Product or Keyword from all the projects of your account.
Restore Archive items
To access the list of the items you archived, scroll down to the bottom of the page when browsing your tracked Keywords or ASINs list, you will then be able to display them by clicking on "Show X archived keywords" for keywords for instance, X being the number of keywords being archived in the project.
As you show the archived items, you have the ability to either completely delete them, or to restore them as an actively-tracked item.