Import from old b2 installation

I have a b2 installation that I’d like to import into my new WordPress blog.

There are lots of docs on doing it for much older versions of WordPress, but none for anything recent.

Am I just SOL, and will have to re-enter everything manually, or is there a way?

Also: on my new blog I would like to display a particular category by default, but any sub-sets displayed by links. How can I do that?