Multipage registration form with Ctools

I'm trying to follow the tutorial on multipage user registrations at http://www.grasmash.com/article/building-multistep-registration-form-drupal-7-using-ctools, but I'm doing something wrong. As it's written, if I put function hook_form_user_register_alter(&$form, &form_state) {, it throws me a Parse error: syntax error, unexpected T_STRING, expecting T_VARIABLE error; however, if I change the &form_state to &$form_state, it doesn't complain.

HOWEVER

It seems as if this form isn't replacing the existing form. There's a button added to the registration form Create new account (the standard Drupal continue button is still there). The rest of the standard Drupal form is still the same (just username and password fields).

Thanks for your help