The edit button (ON YOUR OWN POST). It's one of the White buttons Labeled 'Edit'.. o-o
Members are only allowed to edit their threads, not their posts. (Ex: Editing your Gallery Thread [ALLOWED]) (Bad Ex: Editing a post on your thread or any other of your posts [NOT ALLOWED])
And we can SEE if you edit your own posts, so don't bother trying. You WILL be warned for editing your own posts.