how do I remove meta describe from title on twentyten theme

edit header.php of TwentyTen:

<title><?php
	/*
	 * Print the <title> tag based on what is being viewed.
	 */
	global $page, $paged;

	wp_title( '|', true, 'right' );

	// Add the blog name.
	bloginfo( 'name' );

	// Add the blog description for the home/front page.
	$site_description = get_bloginfo( 'description', 'display' );
	if ( $site_description && ( is_home() || is_front_page() ) )
		echo " | $site_description";

	// Add a page number if necessary:
	if ( $paged >= 2 || $page >= 2 )
		echo ' | ' . sprintf( __( 'Page %s', 'twentyten' ), max( $paged, $page ) );

	?></title>

change it as needed; i.e. maybe delete this part:

// Add the blog description for the home/front page.
	$site_description = get_bloginfo( 'description', 'display' );
	if ( $site_description && ( is_home() || is_front_page() ) )
		echo " | $site_description";

if i understood what you want, you could try to edit this line (from the code i quoted)

// Add the blog name.
	bloginfo( 'name' );

and change it into:

// Add the blog name.
	if( is_home() || is_front_page() ) bloginfo( 'name' );

that would show the blog title only on the front page, and not on posts or pages.