Making changes to the registration form on upfront?

Hi
im looking to make some changes to the fields on the registration form on these three pages
- http://tinyurl.com/p9xfwwx
- http://tinyurl.com/qedvuxv
- http://tinyurl.com/qbhfmxm

See changes here - http://take.ms/dTop3
I want to simply it so that i only have the following fields shown
- First Name
- Second Name
- Email Address
- Password

Support access is ACTIVE until September 15, 2015 1:21 am

Thanks
Tom