You should be able to drag them one at a time to where you want move them. Just place your cursor over one holding down the button and drag to where you want it. When you get it where you want it release the button.
Hi Dave this is good to change the order of the icons but in the same left place of the dock,
WetTornado if you want to move all together the icons to the opposite side you have to check the "Taskbar options" then you'll be able to toggle the left\right position