How do you edit a classified ad title and leave the ad as is?

Thomas Smith

Dave Scadden "Expedition DLS" 9' Pontoon Craft
#1
How do you edit a classified ad title and leave the ad as is? I need to change the # of feet from 10' to 9" in the title of the one classified ad I have posted, regarding the Dave Scadden Pontoon craft. I was able figure out how to correct the ad, but unable to figure out how to correct the thread title, the only option I saw was to delete the entire thread.