Can i change my court order?

me and my sons father have joint custody since may 2009...i decided to give him joint custody because i didnt want to put my son threw such fight...his hours: mon-friday 7am-6:30pm alterbare weekends..Things where great but my ex decided to break the rules. He doesnt fallow the order he thinks he can pick him up wenever he wants and drop him off anytime...know on the court order it says we need to notiyfy each others adress when we move and he hasnt done that. He is very rude towards me and i have recorded arguments of when he calls me just to get my angry..my sons 1year old and is to be starting school sumtime i wanna know if i can switch the agreement to a better..and no im not tryng to throw barbs at my ex he has a bad record and he hasnt proved to anyone hes capable of having 50/50 of our son i have proof but i just want a point of view