Want to add extra fields when using "Rename wp-signup.php"

So...I want to add a couple fields to sign up process (customer address to second part of sign up)

So i have reviewed the tutorial here:
http://blog.ashfame.com/2010/11/add-custom-field-registration-wordpress/

How would I include the extra field when using the feature:

"Rename wp-signup.php"

Thank you for your advise!