"Yes. You can edit or delete your own posts up to 12 hours after they are made. Where the change is substantive, you should mark the post as edited so as to alert viewers to the changed content. For cosmetic changes it's better not to do so. Also, when deleting a post, only a post with no replies will be completely removed from the forum. If your post has any replies to it, the delete function will simply clear the content out of your message, and mark it as deleted.
To edit or delete a post, click on the Edit link, which is located next to the reply link on all of your own posts. "