How to Backup your Blogger Template and Restore ?

That’s it! You now have a backup of your template in case anything goes
wrong.

Restoring Your Blogger Template

1. Go to your Blogger dashboard and click on “Template” in the left menu.
2. Click on the “Backup/Restore” button in the top right corner.
3. Click on the “Browse” button. Then navigate to and select your backup
   file on your computer. (It will be an .xml file)
4. Click the “Upload” button.

Your template should now be restored to the version you backed up.
*Important
Notes

• This process only backs up your template (the design and layout of your
  blog). It doesn’t save your website content (blog posts, images, etc.).
  For that, you’ll need to back up your content separately.
• It’s a good idea to rename your backup file so you can easily identify
  it later.
• Always keep a backup of your template before making any changes, in case
  you need to revert back.

If you have any trouble with the above steps, you can check out Blogger’s
help page or contact their support for assistance.