What do I need to buy to convert a Year 1 of 2 course into the One-Year Condensed one?

The easiest way to make sure you have everything is to go to the program you are interested in, click the "What's Included" tab and then click the "Highlight Previously Purchased Items" button in the upper right of that tab. Add all the items you do not currently own and you'll have what you need. Don't forget your Instructor's Guide!