You can't if you're using a page node. 1.2 will allow you to change the /pages route, but not remove it. You would need an add-on to do what you want.
You cant remove the /pages route with the route changer add-on. Only change it. As Brogan mentioned you need an add-on if you want to remove /pages route.
Technically, in 1.2, you can do this. You can't remove the pages prefix for all pages in one go (you can only change it for everything), but you can remove it on a page by page basis.
