We’ll take a look at the automatic method which can be used to quickly import many posts from your Blogger blog into a WordPress blog.
In your WordPress dashboard, go to Tools > Import then choose Blogger. (You will notice there are several other blog platforms listed here, and the converters for each all work in roughly the same way.)
The next step is to let WordPress Authorize your Blogger account. You should then see the screen on the right. You will have the chance to Grant or Deny Access – choose the first option to proceed to the next step, where you will be presented with a list of your available blogs. You can then select the Import button next to the appropriate blog in order to complete the process!
Imported posts will be assigned to the default category in your blog, so be aware you might need to spend some time reassigning these. If you have WordPress 2.9.2 or later, you should be able to quickly change categories using the Quick Edit function on the Edit screen, which allows you to change category, author, published status and tags without opening the full post for editing.
If this method fails, you may need to upgrade your WordPress version.