Moose may have directions for that on his site.    Moving this to the codes section as this has to do with the All Skin Chooser code.

I believe Moose had a page on a forum someplace that explained how to use your own (or he mentined he was gonna do so)    Hopefully he will see this and help you with it.   Or, you could use the one I made for the portal, and instead of using it in the portal put the choices at the top of the screen.    Can help you with that tomorrow sometime if you want to give that a shot.  Its listed in the codes index under stylesheet something or another.   Sorry, Im on a slow connection today(horrid slow computer) so Im limited to poking around for things today.

If you want to see how it looks and works from the portal click the sibyls simple stuff graphic in my sig .. its installed on that site.   You can also see it on my forum here:  http://madamemmastent.smfforfree.com/index.php

The code and directions for doing it that way are here:
http://www.smfsupport.com/support/smf_for_free_codes/code_stylesheet_swapper_for_portal_block-t9712.0.html

You can do it, as I said, at the top of the forum instead of in a portal block (if you are not using the portal)   Instead of putting the code in the Portal block you would put that part of the code in your header.   Take out the "br's" between each of the style choices so they line up in a row.     If you do need help with that part of it do let me know either here or via pm and Ill take a look at how you are progressing with it tomorrow when I have access to my better machine.

Looks like you got it working good      Good job.