Redesign/configure registration page on PHPNuke site

I have an existing phpNuke site that I need some help customizing for our needs before making it public. The first thing I want to do is redo the registration page(s). Currently you must go through 3 pages before finally submitting the registration. I want to reduce it to 1 page with just a few questions on it. I also need a few new options added to the page that will have to propagate to the MySQL database.