Ok, now I understand. You do not want to edit, you want to delete them.
Did you download the PDFs from the email?
If so then you will need to find them and drag them to the trash.
You can do this easy by using Spotlight to find the location.
Open a Finder window, then type one of the PDF file names into the search box. If you do not know a file name then just type in PDF.
Using PDF as a search term it will find all PDFs on your Mac, then you have to sort to find the ones you want.
Along the bottom of the window will be the path to find the item.
After locating it then just drag to the trash. Make sure to empty the trash or it will still be on your Mac.
Does this help? If it is not clear please let me know.