ok, wordpress uses themes, I think you know that so, there are 2 ways, the first one is is to use your favorite ftp client to go inside your install directory, there you should find a directory called wp-content, inside that there’s a directory called themes, WP puts every theme inside that directory, your theme should be weaver or something like that… find it and enter his directory.
At this point you should see some php files (index.php, functions.php and so on) and a file called style.css, open it with your text editor (under windows use something like wordpad or better, not notepad) and do what I told you in my first reply ??
The second way of editing this file is to open your dashboard as admin and go in the appearance section, look for the “editor” option and click on it, it will open a very simple text editor. On the right of the text editor you’ll find every file in your theme, click on your stylesheet (style.css) and now you’re ready to edit it as I told you…
I’m sorry but I can’t make it more easy than this ??
I hope it helps ??