Couple more details:
Combating intensity day stalling: If you feel you are unable to complete the full 5 reps for intensity day, but are still confident your strength is going up, you can start progressing to 2 sets of 3, then 2-3 sets of 2, then 5 singles until its obvious that is not possible, then 3 singles, then finally a new 1RM attempt
Volume day not driving up intensity day: Transition from 5x5 to 8x3 at a slightly higher weight, or add a back off set.
These are very surface level explanations of Rips work, and the book goes into much, much greater detail about when to use various methods for various types of stalling. I high suggest you pick up a copy of this book if his methods work for you. It is an excellent book and a quick, fun read for those of us that like Rips style. It really breaks down training and makes the reader understand WHY you would change something, and what to change.
Again, buy the book if you have an interest in the science of strength training in general, or happen to like or get results from Rips work in specific. It will be money well spent. It anything I have written above sounds good and you want to understand it further, there are much more details in the book.