We do not delete threads. If you need info updated in a thread use the bad post report and make a request for update and we will evaluate if request if appropriate. We try to avoid problems that might lead to pricing disputes.
I don't want to delete a thread, I just want to delete a reply or post that I made. Is that possible?
No, not possible. Mods do not do threads or posts. But if its against the rules, you might get an infraction and get the thread/post deleted.