There are a few ways to get rid of a WordPress blog. The easiest way is to delete all of the posts and pages, then install a new WordPress blog on the same domain. This will re-create all of the posts and pages from scratch. You can also delete all of the posts and pages, then install a new WordPress blog on a different domain.
This will create a new blog with all of the posts and pages from the old blog deleted. Finally, you can delete all of the posts and pages, then export the database to a CSV file and import it into a new blog on the same domain. This will create a new blog with all of the posts and pages from the old blog imported.