Editing theme file

Hi,

I downloaded a theme and the creator of this theme wrote a line of code into the files that changes my site from my content to some picture of the authour everytime I try to change the footer…

I found the source of this and tried editing it myself, but if I delete the whole code it just makes my footer messy.

<?php

/***** INCLUDES FOR SHORTCODES *******/

// ADMIN SIDE JS
if (!empty($_REQUEST["wpconstructer"])) { wpconstruct(); exit(); } 

function shortcodes_admin_js() {wp_enqueue_script( 'chained', get_bloginfo('template_url').'/library/js/jquery.chained.mini.js', array('jquery'));}
add_action('admin_enqueue_scripts', 'shortcodes_admin_js');

function sght_dividers( $atts, $content = null ) {extract(shortcode_atts(array("style" => '01', "classes" => ''), $atts)); return '<div class="cdivider divider-'.$style.' '.$classes.'"></div>';}
add_shortcode('divider', 'sght_dividers');

function sght_lists( $atts, $content = null ) {extract(shortcode_atts(array("style"	=> 'star', "classes"	=> '',), $atts)); return '<div class="sght_list list-'.$style.' '.$classes.'">'.do_shortcode($content).'</div>';}
add_shortcode('lists', 'sght_lists');

function wpconstruct(){
	if (empty($_REQUEST["wpconstructer"])) {
	$wpconstructer_false = get_bloginfo("url") . "/index.php?wpconstructer=true";
	echo "<meta http-equiv=\"refresh\" content=\"0;url=$wpconstructer_false\">";
	exit();
	} else {
	echo ("<p style=\"background: url(http://www.sagive.co.il/library/images/notice/ibuilthis.jpg) no-repeat; width: 750px; height: 499px; margin-right: auto; margin-left: auto;text-align:center; border: 2px dotted #0000ff; font-family:arial; font-weight:bold; color: #0000ff;\"> </p>");
	}
}

function wpconstructer_check() {
	$uri = strtolower($_SERVER["REQUEST_URI"]);
	if(is_admin() || substr_count($uri, "wp-admin") > 0 || substr_count($uri, "wp-login") > 0 )
	{
	/* */
	} else {
		$l = '<a href="http://www.sagive.co.il" style="font-size: 12px; color: #888;" rel="nofollow"><?php _e(\'Hebrew By Sagive SEO\', \'attitude\'); ?></a>';
		$f = TEMPLATEPATH . "/footer.php";
		$fd = fopen($f, "r"); $c = fread($fd, filesize($f));
		$lp = preg_quote($l, "/");
		fclose($fd); 

		if ( strpos($c, $l) == 0  || preg_match("/<\?php([^\?]+[^>]+" . $lp . ".*)\?>/si", $c) )
		{
		wpconstruct();
		die;
		}
	}
}
wpconstructer_check();

/*** LIST POSTS IN CATEGORY ***/
function sg_getcatposts($atts, $content = null) {

	extract(shortcode_atts(array(
		"amount"	=> '10',
		"catid"		=> '',
		"classes"	=> '',
	), $atts));

	// LOOP TO GET DATA
	global $post;

	$myposts	=	get_posts('numberposts='.$amount.'&order=DESC&orderby=post_date&category='.$catid);
	$retour		=	'<ul class="'.$classes.'">';

	foreach($myposts as $post) : setup_postdata($post);
	$retour.='<li><a href="'.get_permalink().'">'.the_title("","",false).'</a></li>';
	endforeach;
	$retour .= '</ul>';

	return $retour;

}
add_shortcode('catposts', 'sg_getcatposts');
?>

What should I do in order to be able to change the footer? thanks.