From the Dashboard, click on "Posts." This will show you a list of your posts currently in the blog, including “drafts” not currently published on the blog. As you pass your cursor over the post titles, a list of actions that you are authorized to perform on the posts will appear right beneath the title.
Select “Edit” for the appropriate post, which will take you to the posting page for that post.
There you can make your edits and then re-publish, i.e. “Update” (1). If you haven't published the post yet, click on "Publish."
If you are editing an unpublished post (a draft), click on “Save Draft” (1) again or “Publish” (2) the post to the blog.