If you're not feeling very proud of that post you shared when you were drunk last night, you can easily unshare it. To unshare, go to the shared post and hit the share button at the top of the page.
You'll see a new option at the top of the editor, Unshare from, which allows you to remove any shared post from your blog.
If you've reframed a post by adding original content to the share, you can delete it as you would a normal post. This will not affect the original post, only the reframe.