Go to the post(s), click the edit button (probably in the bottom right corner of the post) and change the text to five periods (.....). It should take you a matter of seconds to delete one post, and a couple of minutes to delete 4-5 posts.
Because of the way the site works, there have to be at least 5 characters in each post. You can put 5 periods or simply write 'edited' or 'deleted' and your previous post will be written over.
Laurel and Manu will not delete your account or all your posts for you if you have changed your mind about things you have said here.