Add grain background to your blog main body

This is also a quick update. This tutorial was requested by a person on my Thank you for asking!

To get this grain background on your blog's main body, follow this simple steps! 

1. Go to Dashboard> Template> Edit HTML
2. Search for ]]></b:skin> and paste this code ABOVE/BEFORE it.
.post-body,.content-inner {

3. Save template and you are done!