[Koha] Migrating from 2.2.9 to 3.00.01 once more

[Marty]

I have Koha 3.00.01 up and running on my new old box, yeah!
But I am really confused as how to migrate my data from the 2.2.9 database.
(I screwed it up once already before my other box died)
I know there is a Wiki (http://wiki.koha.org/doku.php?id=22_to_30) but I cannot say that is really helpful for me.
Like: installer/data/mysql/updatedatabase.pl this script will finish the update of the database. Which database? There is nothing in the koha3 database yet? Do I update my old database? Does that move my data?

It seems that this Wiki is left over from the Beta version?

In short, I am confused (I am easily confused). Can somebody just tell me how to get my data (biblios, items, patrons et al) from 2.2.9 to 3.00.01?
It can't be that hard, I think?

Thanks