Default [Q] How to dismount sd card in 20140515 nightly?

Settiings|Storage has no option for dismounting sdcard, instead it's got the "Erase sdcard" option in there twice! Is this a bug? feature??

So there's no way to dismount the sdcard from within this version of KitKat? I tried terminal but it said "file not found" on every command I tried, including parted.