newbie question: how do you scrap facilities?

[Growltigga]

adder_inf

when clicked on a planet (so its info is in the window on the right hand sifde of the screen) if you look on the toolbar, top row about 3/4 of the way over from the left hand side of the screen, there is a funny little button that loks like a box with a green arrow coming out of it - click on that and a list of all facilities on the planet should pop up, highlight the ones you want to scrap and hey presto!!