To use a third-party custom template on your Blogger blog, you need to download that template to your computer and then upload it to your Blogger account. Get your custom third-party template onto your Blogger blog:
Download the custom blog template to your hard drive.
The custom blog template’s designer or Web site should include explanation about how you can download the template.
The new HTML code for your third-party template now automatically appears in the big box in the Edit Template section of the page.
After your new third-party template is uploaded, click the View Blog link to review the look of your blog.
You might want to modify your blog’s page elements after you upload your third-party template. For example, you might need to clean up your blog by changing the order of your profile, updating the archives in your sidebar, or adding a graphical image to your header.