how to copy paste pdf files to messages using ios 0.2.1

tap and hold on the pdf attachment, a sharing popup window will appear, tap on Message green icon, then type in the message recipient, then tap send (blue arrow pointing up)

Where are your PDF's stored?

typically, you can't copy paste PDF's, but you can open up a PDF then tap the share button (square with arrow pointing up), then select messages as the destination.