You may edit/delete your article by logging in and clicking "My Profile" in the top right corner. Once in your profile select the "My Articles" tab. Locate the item you wish to edit/ or delete and click the corresponding option to the right. Selecting "Delete" will remove the article from the site. If you'd like to make some edits then select the "Edit" button. Make the necessary changes to your submission and hit save your article. That's it!
Please note that once you delete an article there is no way of resurrecting it.