From Online Manual
Moderators are able to edit everyone's posts, including their own. There are two methods of editing a post:
To edit a post, select Modify. This redirects you to a posting page where the edits can be made. Make any necessary changes and then select Save.
This can be performed by selecting located in bottom right hand corner of every post. This will open the post box which allows you to edit the post inline, but the interface for Bulletin Board Code is unavailable, so it would need to be manually entered into the post. On selecting Save the changes are made instantly.