There is no way to purchase the book patterns individually; they are only available in the Cocoknits Sweater Workshop book. The book teaches the Cocoknits Method for top-down seamless sweaters, which is used for all 8 patterns and their variations in the book.
Here is some more information about the Cocoknits Method, explaining how it is unique and why it requires a book to accompany the patterns.
The patterns included in the book