Edit "Create Account" registration form for Magento Store
===

I would like to edit the required fields when a customers creates a new account with my store. Currently the form requires the customer to enter his First Name, Last Name, Email and Password. I want to disable First Name and Last Name from being required, maybe even not showing those fields. I just interested on the Email and maybe a username, and of course the password. 

I am currently using Magento version 1.7