The Modern Philidor Defence consists of seven chapters, dealing with different move-orders. Each chapter comprises of a "Quick Repertoire" then a thorough theoretical study in the part "Step by Step"and "Completer Games".
In order to include a system in your opening repertoire, it would be sufficient for you to read the review and see the games and this should not take too much of your time. After this, you can start playing this opening in friendly games at your club, or on the Internet.
After you have amassed a certain degree of experience in the Philidor Defence, you should better study the part "Step by Step" and compare your actions with the recommendations of the author and possibly you might like to correct your playing a bit.
The Philidor Defence will become then a wonderful weapon in your chess opening armour.