can't access user info in sharekit iphone sdk

can't access user info in sharekit iphone sdk

I am using ShareKit iPhone SDK for Facebook, Twitter, Tumblr sharing
functionalities. But in my app I require to log into the app using
Facebook, Tumblr, Twitter (i.e. By selecting any of the option given here,
user can be logged into their perspective account using ShareKit interface
and then directly goes to the main screen in the app). It's same
functionality, like, any web service allows to "Login with Facebook or
Twitter or Tumblr". And then, in Main screen, I will display user info.
(like, email, username, first and last names, birthday, etc.). And when
anyone changes password for any of these account, login screen will be
displayed for the same.
Can anyone guide me for the same? I have searched through some blogs, they
told to change or override base classes of ShareKit, like, SHKFacebook,
SHKTwitter, etc. but in my system I find them locked, so, I can't modify
them.