Remove 'Change Password' Option from ECP in Exchange 2013 OWA

Hello

I need to remove the 'Change Password' option from Exchange 2013 OWA. I have removed it from the pull down menu on the main OWA page by removing the feature from the OWA virtual directory settings, but this doesn't get rid of it from the ECP options (Options/Settings/Password). I found this this article on how to do it:

http://blogs.technet.com/b/ilvancri/archive/2012/06/22/take-away-the-possibility-for-users-in-exchange-online-to-change-their-own-password.aspx

I ran through this and created a new role called 'MyBaseOptions-NoPWD' and assigned it to the 'Default Role Assignment Policy', then removed the 'MyBaseOptions' role. This shows up as having been a success, and I've since found one or two other articles explaining it in the same way, but it hasn't removed the Password option from ECP.

I've restarted all of my Exchange services on all of my servers (it's just in a lab for now, but I have recreated the same problem in my live network), but it makes no difference. Is there a step I'm missing?

I should add I'm running Exchange 2013 CU3

Thanks in advance for your time