Going back from Prefill page to Compose page

In our process, there are a couple phases.  The first phase is Compose/Send Page.  The first phase we fill in email addresses to receive, files to attach, and a subject and message to include.  The second phase, prefills the contract with desired information specific to that contract composing.

The question is, how do you go back to the first phase without having to completely start over from the beginning?

Please help, and thank you