You can find the answer to this exercise in "Answer for Chapter 16" in the Appendix.
16.10.1. Exercise [30 min]
Package up the Animal and Horse classes from Chapter 12 as a distribution. Be sure to add the proper POD documentation for the subroutine. Test the module, install it locally, and then build a distribution file. If you have time, unpack the distribution into a different directory, pick a new prefix, and install it again to verify that the distribution archive contains everything necessary.