I went through the tax preparation and printed my returns to see them on paper. Now I cannot go back to make changes. How do I go back into my return and make changes?

If you have not yet actually filed, you can make changes.  Here's how to reopen your return interview to edit anything.  

Log in and at the Tax Home look for a link "Add a State."   That doesn't really add one, but will reopen the interview.

I think this is going to work.  Thank you very much

You're welcome.  Good luck.