is it possible to add or change things thats in the portal
yes, its all template driven or supported by plugin hooks
do you know where i could find 1
what do you want to do first of all? templates are in the ACP under Themes and Templates. Find your template set and then under the Portal item
may be its better to use
proportal so that customizing could be easy !
I actually find customizing the portal page directly in its templates easier .