Hi guys. One thing I can't see any clarification of in the Lion GM installer is the ability to upgrade vs clean install. I just want to upgrade my current Snow Leopard installation, and maintain all existing files/setup etc. I don't want Lion to do a clean install. Where in the installation process am I meant to be able to check this? The Customize button is all greyed out and I have no idea of knowing what the installation will do. Thanks.