Change main class for forums?

When I started the game I was a THM, but since then I've changed to Scholar/Arcanist. I'm currently 37 and my THM is 26, and I'm tired of these forum restrictions because of my lower level character.

How can I change my main class for these forums so I'm allowed to post more than twice?

Edit your character info (here). I think it just uses your highest level as your main however.

In the upper right of the forum under Welcome (your name) is Settings, then click on character settings. You can choose what class on your character to use by the drop down menu.

Just an add on. I believe it uses either:

1) The highest level Class you chose from the 3 drop-down menues.
or
2) The far 'left' drop-down menu

As the one it displays.