Firebug will help you with the display, but to change the position of something on a page, you will need to alter the underlying page template.
First you'll need to go to the template directory for that template, then look at through the folders and find which php file controls that view.
Then move the block of code that controls the placement of the subcategories to the top of the page.
This will be a lot easier for you if you go through the template course so you understand the template.
Cheers,
Ed