Then continue doing what you are doing. No demands, no step up! First you build a strong trusting bond before anything else. If he want to be on your shoulder, let him, but don't touch him! Give him some treats (you can put them in his bowl, then walk away) and do that often. Feeding is caring (and also a way to tell them that you love them) in parrots languish. You will see that if you have patience in the beginning and take it slow, it will go very fast to tame them, but if you don't every demand or if you scare them/or put to much pressure to them it will go really really slow. And once you have created a strong trusted bond, you can do almost anything you want with them. So it is worth it!