Originally Posted by Mrs_Often
I think, but I'm not 100% sure, that if you click that scary button, you will get a warning first explaining to you that if you click "OK," you will delete the book forever, and are you really really absolutely sure you want to do this...
I assumed this as well because - well just about everyone gives you a second chance before you delete something FOREVER!!!
But I tested it on a couple of previews that I didn't want anymore and it was one click and BAM! they were gone.