Within the four-hour window for editing:

-- If your post is a reply, you can delete it altogether. Click on [Edit] and look for a [Delete] button.

-- If it's the top post of a thread, you can use the [Edit] button to take most of the text out of it but only a moderator or administrator will be able to remove the thread altogether.

Even outside the time window, you can use the Report button () to ask that your reply or thread be removed. Usually the first team member to see the report who can do anything about it, will.

You could PM someone on the Community Support Team instead. If they'd just left, though, they might not get your message for several hours even though their status icon () continued to show them as logged in for a while longer.

Depending on the forum, not all moderators may be able to edit posts there. When I receive a deletion request for a forum I don't have the "keys" to, I have to pass it along to someone else on the team -- another reason the Report button is often faster than PMing.