What are you trying to override (the general, main layout or perhaps the layout for a specific class like a Folder or Article)?
Which documentation did you follow and what is going wrong? What kind of example do you need?
Did you read the tutorial at http://www.ez.no/ez_publish/documentation/building_an_ez_publish_site/setting_up_the_main_layout/creating_a_barebone_main_template? It shows you the basic principles.
