One recommended method is to mix the seeds and pellets (say 25% pellets, 75% seeds) to start for a few days and then slowly over the course of a week or two, increase the percentage of pellets and decrease the percentage of seeds until its 100% pellets. A drastic switch can be hard on birds (although it does work for some!). Good luck, they will be much healthier on pellets. seeds can always be a treat on occasion for most parrots.