Unbloggerized is a free Blogger template with 3 columns, left and right sidebars, footer columns and social bookmarking icons.Author: UNacademia.
1. Unzip the template file you downloaded (you can use 7-zip or WinRAR for this task).
2. Go to Blogger dashboard, then Theme.
3. Look for dropdown menu and click on it. Then select Restore and click Upload.
4. Select the .xml file from the directory in step 1 and upload it. Thats it, your template should be installed.
Unbloggerized Blogger Template