I have a 3-document attachment in my email. I only wanted to fill in 1 of the documents so that I can fax it to another party. How do I delete the other 2 documents from the one I want to send?

I received an email which contained 3 documents which are "packaged" together.  I can't figure out how to separate out the 1st & 3rd docs from the one I wish to forward.  I filled out the 1 document which I want to fax & emailed it to myself so that I could see how it appeared.  I do not want the other person to view the other 2 documents but I can't figure out how to delete them.  They accompany the document I attach to my email even after I have "x-ed" them out at the top of the file.  Help!