Error in reformatting hard drive
I used this article "HT201909: Format external drives to Mac OS Extended before using with Aperture" but I keep getting "Disk Encryption failed with the error: Couldn’t eject disk." with completion of step 9. What do I do? I am trying to reformat my Iomega external hard drive (which they discontinued so they are no help) to be used with my Mac. There is data on there, but I am fine erasing it. All I want is to be able to use my hard drive again.
MacBook Pro (13-inch Mid 2012), OS X Yosemite (10.10.1)