You can place reorders easily after you login to your Account. Just follow these steps:
Login to your Account > Click 'MY ACCOUNT' at the top of the website.
Click the 'Purchases' link in the menu.
Find the Order you want and click on it.
Click the 'Reorder' button at the top of the screen.
Review the items in your cart (edits can be made before reordering).
Checkout as you normally would.