This tutorial will show you how to hide both source and via links on your blog.

Dashboard> Blog> Customize Theme> Edit HTML 

Now scroll down to find {block:Posts} somewhere within your theme’s code

This is the Posts Block which allows Posts to appear on your blog. So once you have found it you will need to copy the following code:

{block:ContentSource}

<!— {SourceURL}{block:SourceLogo}<img src=”{BlackLogoURL}”

width=”{LogoWidth}” height=”{LogoHeight}” alt=”{SourceTitle}” />

{/block:SourceLogo}

{block:NoSourceLogo}{SourceLink}{/block:NoSourceLogo} —>

{/block:ContentSource}{block:ReblogParent}{/block:ReblogParent}

This code will be placed right blow {block:Posts} 

Update Preview> Save and you’re done!