Thanks for reporting that. I checked this. So, I will copy this as a work-item. This way the product team will be notified and other user can vote this.
In drop 9 this Appendix says that the How-To(s) would be included included in the respective Chapters topics in the future.
So, please take into account that the product team is in process of updating the documentation for the final release.
On the other hand, as a workaround you could continue using the help file, which is part of Drop 9 as well as the
documentation on MSDN (the online documentation has not been updated yet for Prism 4, but in some cases might be pretty similar).
Thanks again for your feedback.
Hope this helps.