This screencast walks you through the process:
A few notes about the tool:
- The final post is in English only; translated versions for non-English blogs will be available next week
- Once the migration is complete, you can delete the final post from your blog’s dashboard by going to Edit Posts and selecting the post for deletion. It will remain on your FTP blog so that visitors to that blog will know about the new location.
- Once you migrate your blog to Blogger hosting, you won't be able to return it to FTP publishing