HowTO remove the link to the image??

Here’s my problem… can’t get the images to open in lightbox,thinkbox, prettyphoto or any other js plugin.
So I want to remove the link to the image… how hard can that be?
Well it’s seems it’s not that easy either…
What I did try was to remove this line:
$out .= " <a target=\"_blank\" href=\"" . $picture["link"] . "\" title=\"open image\" class=\"open\"></a>";
from nggSmoothSharedFunctions.php
But the plugin doesn’t work then like it should and it breaks.

Is there any other way to solve this?

Thanks in advanced!