If you are site admin, do the following:

• Go to: YOURSITE.COM/admin/content/node
• Select "Type" is "Blog" and then click "Filter"
• Check the blog writings you want to remove
• From "Update options" select "Delete" (or what ever you want to do for the checked items)
• Click "Update"
• You're done

OR... use "Advanced Search" at:
YOURDOMAIN.COM/search/node

Drupal is a web-based content management system. Text and pointers to other kinds of content are stored in a database and are dynamically retrieved, composed, and presented to a user in response to a request sent via a web-browser.