Removing sidebars in wiki incsub_wiki.php to achieve full width

Hi, I simply want to copy and modify the default incsub_wiki.php in the /wp-content/plugins/wiki/default-templates/ directory and copy it to my themes directory. As a test, I'm using twentytwelve, so I would copy it to: /wp-content/themes/twentytwelve

So, I thought I would simply remove this line (line 32):

<?php get_sidebar('wiki'); ?>

... and that would remove the sidebar and make everything full width. It did not. I'm not a Wordpress developer, just a guy who wanted to use a plugin. Can you advise what I can do to use the wiki on a full width page w/ no sidebars?