This is a hard one to do, but it will set you up to be successful. Go through your refrigerator, freezer, and pantry looking for any foods that are unhealthy or highly processed. You want to look for chips, breads, sweets, treats, ice cream, candy, TV dinners, pre-made meals in a bag or box etc etc. Remove these items and put them in a box, you can donate them to a family in need or give them to a local charity. After you have removed these items from your kitchen do not buy them anymore. Only buy whole natural minimally processed foods. You want to shop the perimeter of the grocery store and avoid the middle aisles as much as possible. Only shop the produce department, meat department, and dairy department. The vegetable/fruit/meat aisle in the frozen foods department is a good section as well. Just make sure to look at the ingredient list and avoid the sauced and breaded items, only buy plain vegetables/fruit/meats. This is the rip off the band aid approach.
Another approach is to do this slowly over time. Don’t buy anymore of the processed foods once they are gone. When you are finished eating the chips and bread don’t buy it anymore. This way you don’t have to donate the food, and you can eat it, but you won’t buy anymore when its gone.
I do realize this is an extreme approach and if you have children or a spouse that is not onboard then this is pretty much impossible. If someone’s health is a concern, then the family will need to compromise. Maybe each one of the other family members can have 1 processed food in the house they don’t want to give up. They can also put the food in a hiding spot only they know about. It’s not an ideal situation, but if someone has an eating problem and food is in the house, they will eventually eat the food. If it’s not in the house, then the temptation is not readily available.