How do I deactivate a program?

Mobile@iron was installed on BB Passport. I have decided to uninstall it (push on Mobile@iron icon and the delete icon that appears next to it), but the programm seems to be still installed in the record of Google app store. When I click on open, it does not work and the other option is 'deactivate', which seems to be required before uninstalling. The message is "this app is a device administrator and must be deactivated before uninstalling". I am stuck. Could you help me please ? Thank you in advance.

I'm guessing it's an Android app so use Ghost Commander to find and delete it.

PassportSQW100-1/10.3.1.2576 O2 UK