She has been on human food and is way over weight how can I help her lose the weight safely she is six years old and a Bichon friese.

Do you live near a pet food store (that sells nothing else)? That's where you get special dog diet food, or from your vet.
Grocery store brands aren't as healthy, especially for a diet, because the cheaper the food, the more filler it has in it. Filler literally goes through the dog, so it's nice to have less poop. Cheap dog food just doesn't have the best ingredients for a dog anyway.
Even small dogs should eat mostly dry kibble, with wet food only a small part of a meal.
Talk to your vet about your dog's specific needs. You don't need to get into super expensive stuff, but it will cost more than you might pay for a healthy dog.
Stay away from obscure brands. Too much contamination these days. A friend's dog just had to be put down from expensive food that had listeria.

Diet and exercise. I would talk to your vet, get a complete checkup to make sure that there's not a medical reason for her obesity like a thyroid issue, and then ask for a recommended dog food, and exercise routine.

It will take her some time to get used to eating food that's meant for her, instead of people food, and she may not eat for a day or two, but hunger will win. If she is going to eat human food, plain rice and skinless/boneless chicken (cooked without seasoning), is okay to feed her. But do try to get her on a good dog food, that would be best.

Good luck.

Ask the vet to recommend the food, schedule and quantity. Have some quality treats, too. If you simply stop the over feeding, the dog will quickly loose weight by being fed the appropriate amount for their ideal weight. Take him for a couple walks a day too. Don't overdue - limit of shape people, the dog needs to get fit over time. So start with some walks.