The method retDAC describes only works for about 2 minutes after creating the thread. Once it gets "locked in", doing as they describe will only change the title on the top of that particular reply, but it will still show up in the main thread listing as the old title. It's similar to editing your reply - if you catch a mistake quickly, you can make an edit before the little note appears at the bottom of the reply stating an EDIT was made.
This is the way it has worked for years unless they have changed it recently. The mods can edit a title for you if you ask nicely.
(BTW, I'm not a mod. - just look down at the lower righthand corner of the forum listing you are in to see the moderators listed)
