[Zope] zope buttom

Dear gentlemen, I have just started with zope! I am impressed with zope capabilities! Since, i have a doubt: When i go to http://<fqdn>/manage i get a upper layer on my browser that shows Zope Logo. May i switch it to my company logo ? On the left layer i get a link to "Digital Creations Refresh", may i change it too? Would this be ilegall (About copyrigths concerns?) Thanks a lot for your time and cooperation. best regards. -- Good advice is something a man gives when he is too old to set a bad example. -- La Rouchefoucauld