Open up your launcher and click on the tab labelled "Installed Content". It should contain everything you've put into your game via the launcher, including CC. From there it's just as simple as selecting what you don't want and uninstalling it.
A quick tip: Some CC (like makeup) doesn't fit into any of the categories at the top of the launcher, so you have to keep it open to "All" if you want to find it. Also, you can't uninstall content while the game's running. Hope that helped!