This three step tutorial will help you keep your blog safe.
If you cannot follow the screen shot the read the step after the picture
Go to Blogger.com Settings ==> Other== > Export your blog.
select the orange “Download Blog” button from the pop up window and a file will be downloaded which would be in “XML” format.
You can save the file in on your hard drive or clouds like Google drive,one drive,and drop box.
WHAT IF I WANT TO BACK THE TEMPLATE ONLY?
Here is what to do:
Go to blogger dashboard
==> Click on template
==>click back up at the top right
==>click download full template
Here is what it should look like