Cancel half sent Chain Campaign

Cancel half sent Chain Campaign

Hi,
 
I've created a chain campaign but realized I made a mistake on the email subject.  I've paused the sending of the campaign and want to edit the subject line before resuming sending.  I can't find a way to do this.  If I clone the chain campaign, it creates an entirely new campaign but then I have the problem of not being able to send to the unopened list from the initial campaign.  Any help on how to either edit the chain campaign or stop and delete it and create a new one?
 
Thanks!