How to change the order's category

Hi.

For my first blog with wordpress, I used Thematic with Gallery.

I began to change the theme but I have a problem :
How to change the order of the category. I try the plugin called “My Category Order” and try to change the category-template.php but nothing work, the order in the top area, beside the home button never change

I think that I must modify a file from thematic or gallery but I don’t know what is it.

Anyone have an idea?

My website : https://spome.fr
The category are “A propos du site” and “Une vie de geek”
I want that “A propos du site” appear in the second place.

Sorry if I made some mistake but I’m French