Changing settings on check box in dropbox sign after sending

Hi,

I just did a pretty long document in Dropbox Sign that had four different signers over 18 pages! I sent it off to be signed in a particular order. The first person just notified me that they cannot successfully sign unless all of the checkboxes that I set up are checked off - I did not want that!

Is there a way to go back into the document and just change the settings on the checkboxes to allow him to choose some and not others??  I tried to open the document with "preview" and there's an "edit" option, but it just opens a blank document without any of the fields, and I'm so upset at having to do this all over again.  Please help if possible!