How to create and use a template for a category in K2?

I'm working with Joomla 1.5 and K2 2.5 and I don't know how to give an specific style to a category, I still don't understand the "override" thing.

I've been following this tutorial:

http://getk2.org/documentation/tutorials/item/174-templating-with-k2-and-the-concepts-of-sub-templates

My categories still have all the same style, what I'm missing there ?

I've been carefully (I think so) placing all files with no success so far.

Please check:

• Choosing the right template on the backend (K2 -> Categories -> Edit Category -> Category Item Layout (Tab on the right) -> Select a template).

• If you don't see the name of your custom template there, then double check the path of your template.

• In order to have a different css file (one for each category template if you want) from the K2 one, install this plugin:

http://www.jiliko.net/extensions/css4k2.html