What do i do if i cant sign HELP HELP PLEASE more info?

what do i do if i got scamed by someone and i mean password for msn thats got all my info like my ea.account my xbox.com account but the thing is i dont no how to change my password for msn so then he wont be alouded to enter it but my ea account wont let me sign in and also i cant play skate 3 online now so what do i do and i remember my ea account password and e-mail but i dont let me sign in on the website aswell PLEASE PLEASE HELP!!!