Follow this simple guide to install your Favorite Blogger Template:
1. Click on the Download button and save file to PC (.xml format).
2. Log in Blogger dashboard.
3. Go to Template section → Backup/Restore.
4. Click on Download Full Template to Backup your previous template.
5. Upload a template from a file on your hard drive by click Browse option button.
6. Click Upload button, a confirmation message will appear. Click on Keep Widgets.
Now you're done.
Or watch the clip below if you're still confused: