The most important configuration files can be found under your KonaKart installation directory at:

webapps\konakart\WEB-INF\classes\konakart.properties 
  and
webapps\konakartadmin\WEB-INF\classes\konakartadmin.properties

They can be edited using any text editor. Alternatively, they can be edited from the Configuration>>Configuration Files section of the Admin Tool. Note that most changes will not take effect until KonaKart is restarted.