How user can edit,delete or unpublish his blog post?

First go to blog and click on my blog. It give a list of blog posted by the logged person. Refer Fig 1

Note:- Blog operation edit, delete ou unpublish of a blog can be done by the person who did the blogging.

1. At the top of your dashboard, click the module access icon > Collaboration> blog> My blog
   
2. Perform the Edit,Delete and Unpublish to perform the editing, deleting and un-publishing the blog post