How to migrate from an old classic Blogger template to the New Blogger template

We get frequent complaints about bloggers not being able to see the Blogger Layout. If you have migrated from an old Blogger account to the New Blogger (formerly Beta) account, your blogs will still be using the old classic template. To check whether your blog is using the old classic template or the New Blogger template, refer to Old classic Blogger template or New Blogger template?.If you are