There aren't step-by-step instructions or a screencast for the exercises but you can post questions about specific ones in this forum (start a new thread for each and give them descriptive titles) and I (or someone else) can help. If you really get stuck, let me know and I can make step-by-step instructions.
You may also be able to figure them out by re-reading the lesson. None of them should require huge leaps of intuition. (Although sometimes a hint or two might not be amiss ;-)