1) Uninstall your current copy of Muse.
2) In the Apps panel for the Creative Cloud application in the "Find New Apps" section choose "Previous Version" from the "Filters & Versions" popup.
3) When the previous versions are shown (and no version of Muse is installed) you'll be able to select and install Muse 2014.1 from a popup that will be next to the Adobe Muse entry in the apps list.
You'll have to specifically decline the update notices on each launch of 2014.1 once you've installed it.