The easy way of doing this is to compare the header.html
with one of the standard themes, you should be able to see what all I took out.
Then you can modify the theme by adding in the code needed for the lang menu.
I will look over the code and see what I did when I get time, right now I am very busy, trying to get my house ready for winter. I will see what I can do, but in the mean time take a look at the code.
Thanks.