Now that you have downloaded your theme from, http://wordpress.org/extend/themes/ you then need to extract, that is unzip the archive to your local computer. This will create a folder, you simply upload this via FTP into the themes directly for of your Wordpress Blog Site which is shown below
Directory strucutre of Wordpress Themes
Your next step is quite simple. Head to your wp-admin page of your site, in the structure: www.yoursitename.com/wp-admin You will get a page the same as below
Wordpress Log in Page
