The second step couldn’t be easier conceptually:
Stop engaging with your screens while walking.
You are not that busy.
In reality to implement this is much harder than it may seem. I suggest you take this in three sub-steps:
Notice when you are using your screen whilst walking.
Delibrately pause your walk if you cannot stop yourself engaging with your screen.
Finally stop letting your screen control your movements.
To build this as a habit will take multiple weeks. Try and achieve one whole week walking free and your awareness of how much you are being drawn to your screen will dramatically increase.