Exercise
In this chapter, there was no walkthrough because the refactoring process is quite involved and would have taken up a decent chunk of time and space.
Use this opportunity to try refactoring yourself. Use a systematic refactoring approach to break down the change to React Router into many small steps. At each step, you should still have working software.
You can find a guide on how to approach this type of refactoring at https://reacttdd.com/refactoring-to-react-router.