I would like to remove the default sidebar from my template, it is not needed and I do not want to confuse the user that will be using the admin panel. I have created my own sidebars that are a bit more descriptive to hold content throughout the site.
If you mean the default WordPress Widgets, you would add this to the functions.php file:
Where it says Sidebar2, is where you can add your title for the sidebar position. Just be sure it is relative to the actual position.
if you using twentyeleven theme look for
in functions.php (somewhere @ line 422) and comment it. This will disable the default widget holder from admin area.