Build a Website (Amazon webservice enquiry)

Hi, I have recently migrate my website from 1&1 Vps to Amazon web service. I have asked the freelancer to also create a ftp account for me, which he did. However, my web design couldnt make any changes to the ftp, i think there is something wrong with settings so he is restricted to make any changes. I need someone who is professional in using FTP and help me to resolve this problem so my web developer can continue working on my project. He sent me this message: Hi sir i have done all the css changes but i cant change many things just because i cant upload the files and i dont have permission to upload files so please ask your friend who migrate the site to allow or change the permissions so i can modify the files and i can continue [login to view URL] you!