i am running 6.0 and i would like to upgrade to the latest build of 6.1 I would like to have the ability to switch back to version 6.0 if i need to. The issue is that you can't upgrade from 6.0 to 6.1 ES build directly. You need to use the initial release of 6.1 then upgrade to the latest ES. Once i upgrade to the latest ES i will lose the ability to switch back to a 6.0 version. What can i do about this?