ok for the home page, I did what you said and it is resolved.
For the twitter picture I also changed the picture with what I wanted.
However for the link,
The code is like this when I looked at the header file:
<p> <a href=" <?php echo theme_twitter_link_show(); ?>"><img src="<?php bloginfo('template_url')?>/images/genel_siyah.jpg" alt="" /></p>
the question is, I could not find the theme_twitter_link_show() function anywhere, even in the functions file or header file of index file thus can not modify the # link.
By the way, just for my learning, how were you able to see the source code like you wrote above? All I could see was the code below, when I right clicked to see source code:
<p><img src="http://www.robothaber.com/wp-content/themes/redtime/images/genel_siyah.jpg" alt="" /></p>