Use Username instead of Email for identity in Asp.net mvc5

Whenever I create a new application with visual studio 2013 express for web and using the individual accounts authentication and i hit the register button I notice that it implements ‘Email’ instead of ‘Username’ and the same is in the LoginViewModel as it uses Email to Sign in instead of Username. How can i change this to use Username instead of the default Email without trouble? Also i would like to know how to convert the default ‘guid’ that is a string type to ‘id’ (integer type).