Switch from blogger to wordpress.org

Hi,
I have done that before and it’s really easy to do with the automatic importation tool.

Now my problem is the following:
I want to switch to wordpress.org. The problem is that I have my domain name on that blog so I can’t open the new self hosted blog.
How should I do this? Any way I can simply open a wordpress.com blog, transfer my content to that blog and then transfer the domain name?

What would be the best way to do this?

Thanks lot!