As per FAQ "If you would like to edit (or delete) your posts, you can do so within 8 hours of making the post. After that, it is not possible for you to edit or delete the posts you have made here." "There are two options you have for getting a post altered (or deleted) that was written by another member (contacting moderators/administrators to do it here is not an option you have). The easiest method is to contact that member directly. They have the ability to edit their own posts for 8 hours after making the post. If the time frame is beyond 8 hours, the original poster can request the post be edited by an administrator (the request may or may not be approved)."
From the FAQ also "If you have registered, you will be able to edit and delete your posts. Note that the administrator can disable this ability as he desires. Your ability to edit your posts may also be time-limited, depending on how the administrator has set up the forum. To edit or delete your posts, click the button by the post you want to edit. If your post was the first in the thread, then deleting the post may result in the removal of the entire thread. After you have made your modifications, a note may appear, which notifies other users that you have edited your post. Administrators and moderators may also edit your messages but this note may not appear when they do so."