You may only edit or delete your own discussion post. Your instructor may also control whether or not a student can edit or delete a post.
If you need to change or delete a post, and the options aren't available to you, contact your instructor.
To make changes to your post:
Open the discussion forum.
Click the title of your post to open it.
On the right side of the title, click the ellipsis (...) and select Edit to make changes to your post, or click Delete to remove your post.