How to use Community Builder for registration?

I'm assuming you mean you want to use the registration form when a user clicks the "Register for this site" link in the JFBConnect module. If not, let us know.

To do that, if you're using a template override for Community Builder's standard registration process, you should just need to change the "Registration Component" setting in the JFBCLogin module. That setting sets where the Register link goes to, and for CB, it should go to the normal CB registration page.

If you're using a whole separate page, you can change that link in the /modules/mod_jfbclogin/helper.php file. Just search for $registerLink, about halfway down, and you'll see the section for Community Builder. Change that to whatever custom link you want.

Hope that helps, but if you need anything else, just let us know.

Thanks,
Alex