You mean, under Meta?
I was able to test change it, by modifying the following:
wp-includes/general-template.php, line 194
Look for this paragraph
/**
* Display the Registration or Admin link.
*
* Display a link which allows the user to navigate to the registration page if
* not logged in and registration is enabled or to the dashboard if logged in.
*
* @since 1.5.0
* @uses apply_filters() Calls 'register' hook on register / admin link content.
*
* @param string $before Text to output before the link (defaults to <li>).
* @param string $after Text to output after the link (defaults to </li>).
*/
function wp_register( $before = '<li>', $after = '</li>' ) {
if ( ! is_user_logged_in() ) {
if ( get_option('users_can_register') )
$link = $before . '<a href="' . site_url('wp-login.php?action=register', 'login') . '">' . __('Register') . '</a>' . $after;
else
$link = '';
} else {
$link = $before . '<a href="' . admin_url() . '">' . __('Site Admin') . '</a>' . $after;
}
echo apply_filters('register', $link);
}
change this line
$link = $before . '<a href="' . admin_url() . '">' . __('Dashboard') . '</a>' . $after;
I don’t know how many other instances it will change, but it surely does change the link in the sidebar.