I found this in one of the discussion threads on Amazon.com.
In the web browser settings you want to select "Clear history"
Deleting from carousel:
1. To clear apps: settings-applications-Filter by ALL APPS - App Manager-clear data.
2. Delete a video:settings-select more-applications-amazon video- clear data.
3. Clear web pages: web-menu icon- settings
It works!!! All your books and periodicals remain. It's a quick and dirty way to clean up the Carousel when needed.
Now if we can get some customization options for it, that would be great. We should be able to select what content we want to show up there. I don't want my apps and web browsing history there. The favorites shelf is good enough for day-to-day app access and movies/tv shows. And we have browser bookmarks.