1. Login to your WordPress admin dashboard.
2. Under Dashboard ., hover your mouse on Posts and click on "All Posts".
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3. Hover your mouse on the "Hello World" post and the "Trash" option will appear. Click it to remove the post.
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. Now do the same with the sample page by pointing your mouse on "Page" in the Dashboard . and then choosing on "All Pages".
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5. Choose "Comments" from the dashboard and then the "Trash" option will appear. Now click it.
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After you take these steps, your blog will be clean, without sample posts and comments, and you can start blogging.