In your browser, go to your wp-admin. Then, select the option presentation. Select the CLASSIC theme.
Now either by using your ftp program or wordpress, open up the header.php file in the classic theme folder (go to wp-content>>themes>>classic) and delete EVERYTHING in it. Now, place your skin codes at the very top and this code right below it:
So your header.php file should now look something like this:
Be sure to edit the path and insert yours. Now your blog should match the rest of your site, however you still have to edit the index.php and comments.php file in the classic theme folder, so you can customize the look of your blog to your liking =].
If a sidebar is showing up or something, you may have to do an additional step. This step is to get rid of the sidebar (since you already have one w/ your different skins). Either you can open up the footer.php file in the classic theme folder and remove this code:
OR, you can just remove all of the coding from the sidebar.php file. I'd recommend the first. Please note that when you do this, you will not be able to have certain wordpress plugins that require you to use your sidebar.php file.
If for some reason things are not working out for you or I need to clarify things, then let me know and I will try my best to get to better this tutorial.
<? include($headervar.$extension); ?>
<?php wp_head(); ?>