In order to change the sidereel image you'll need to change the following code in the header template
Code:
<ul id="scroller">
<li><img src="{$mybb->settings['bburl']}/themes/sidereel/reel4.jpg" alt="Firehouse" width="210" /></li>
</ul>
Simply change the image url to the new image you wish to use.. your image must be 200px wide by 1600px tall in order to work without breaking the theme.
wils172
ThemeFreak