In the book he takes almost this example. Once a week (after doing grocery shopping for example) prepare some fruits: peel and cut them if applicable and place

In the book he takes almost this example. Once a week (after doing grocery shopping for example) prepare some fruits: peel and cut them if applicable and place them in containers in your fridge. Then, when times comes to have a snack it's really easy to eat fruit vs. something else. That would be the "make it easy" rule. You could combine it with the inverse of that same rule rule for junk food: "make it hard" and don't buy junk food during grocery shopping.