Unfortunately, you can't change it. Pagemason is meant to be template driven with pre-made templates where you need to choose one that is closest to what you want. You can use a web design program such as one of the free ones like at http://coffeecup.com/freestuff or http://kompozer.net instead of Pagemason or even better would be to use a CMS (Content Management System) like Wordpress or Joomla which also use templates but offer greater flexibility and the ability to add countless free plugins to alter the look and how they work. We have auto-installers for them in both Softaculous and Fantastico.