How to delete stacks?

How i can delete stacks? I can't find delete/remove button and removing all the items on the "stack" doesn't help...

You can delete custom made stacks in the stack's detailed view. In the right column, there is the option to edit or delete your stack.

Thanks :) Do you know is there anyway to delete already existing stacks?

Np! You can't delete the default stacks such as "Games I Want, Games I Own" etc; those are tied into the functionality of the site. A example of this functionality in action can be found on any gamespace like: http://www.gamespot.com/beyond-two-souls/summary/ Click the controller icon in the header and you'll see three default stacks for quick addition and removal of that game.