I migrated all my blogger.com content to a new site These are the final steps I took when moving the content.

• My blogger site was linked to a subdomain e.g. blog.mysite.com so I created .htaccess rules to redirect the blogger content as much as possible to my new content
• On blogger.com I created a final post which said “this site has moved”
  • this included links to the new blog post index
  • and included links to the new RSS feed
  • this post was to allow anyone subscribed via RSS on blogger to change their feed
• In blogger, set all posts (except the one above) to draft mode
• In blogger use “Settings \ search preferences” to write a custom message for 404 the “Custom Page Not Found” Message
• Remove any widgets that refer to blogger content and any links in the template that reference blogger content
• add a menu bar entry that takes people to the new blog