How do you retrain a dog to stop using puppy pads indoors and toilet outside instead?

Allow the dog to continue using the puppy pads while you establish a cue word that means it's time for her to relieve herself, such as "Toilet" or "Get busy." Once she is using the pad in response to a command, you can slowly move the pad, inch by inch, as the days go by, to a different location, while instructing her that this is where you want her to toilet with your command. Now, keep a pad on you and place it on the desired toilet spot outside. Give her cue words, and when she goes, make a huge fuss of her. Then scatter a small amount of soil or grass or whatever substrate is your choice onto the pad. Gradually remove the pad.