Need help!!!

Ok I am new to joomla, and I have an existing site that is running joomla 1.5. I gave been trying to upload the mobile joomla file, and it keeps going to a page that says bad request every time I try to upload it. I downloaded 7zip and unpacked the tar folder. Now here is where I need help. How do I upload these. I'm assuming upload by directory, but I have never done it this way, and wanted to see If u guys could help. Thank u for any advice!!!

Just upload it to tmp directory in joomla's root (<joomla_path>/tmp) and then click "Install from directory" in joomla's installed (by default installation path here is exactly path to joomla's tmp directory).