Removed sidebar, what to do to actually free the space?

Using the default theme (Kubrick) I wanted to remove the sidebar, so I went ahead and removed <?php get_sidebar(); ?> from page.php and from index.php as I’m unsure witch would have been the “correct” to remove. And lo and behold, the sidebar is gone. But looking at pages with a bit of text on them, it’s not actually gone. Just invisible sort of, as the space it used to be is unavailable for me to use. Just look at My Page, the text should have used the whole width of the header.

What do I have to do now? I’ve tried searching the forums, but I can only find the same question, not an answer. Please help!