All you have to do is add your products to the product boxes, and link the Buy Button to your payment processor. Then, just add all your sales copy or other content.
The Buy Button price can be changed right in the html, or use an html editor like Dreamweaver or NVu.
You get all the .psd files for the graphics, so if you wish to change the color scheme, you can simply change the price on the button graphic in Photoshop and then export the entire button graphic as a .jpg, instead of slicing the graphic and creating an html button.
