My boy is exactly like yours. Yes, he is 好百厭 but I don't think we can do anything to change the stiuation. He is just 9 months old. According to this issue's baby-mo, 好百厭 babies are actually clever baby as they know how to show you what they want. You can continue to teach them not to move around when changing diaper but at the same time you have to accept that they will not listen to you (at least for a period of time) .
Just keep on telling them what's right and what's wrong but in no way that you have to expect them listening to you immediately. They are too young. I am sure that they will know it eventually.