what did you try to change in this section:
<div id="site-info">
<a href="<?php echo home_url( '/' ); ?>" title="<?php echo esc_attr( get_bloginfo( 'name', 'display' ) ); ?>" rel="home">
<?php bloginfo( 'name' ); ?>
</a>
</div><!-- #site-info -->
and what are you trying to change it to?
this part: <?php bloginfo( 'name' ); ?> outputs the site title; and the other part generates a link to the home page.
I dont the stie title to be there. on the left side in the footer, there is the site title, the same that is in the header. the name of the website. but i want something else to be there. how can i do that?
told you already – change <?php bloginfo( 'name' ); ?> to ‘something else’
if you want to link the ‘something else’ to somewhere else, then it gets more complicated; change the section;
example:
<div id="site-info">
<a href="http://linktosomewhere" title="some lnk title" rel="whatever">
'something else'
</a>
</div><!-- #site-info -->
