I am assuming you meant unauthorized? Well then you would need to remove it. If it won't just remove or uninstall then you are going to have to look at saving all your personal stuff (contacts, music, videos, photos, etc.) to a cloud account, google account, computer, etc. and then "Hard Reset" the device.
NOTE: Doing this will clear 'all' the data on your phone, so it is suggested you not choose this option unless you have to, or aren't worried about losing anything on the device.
Be sure you back up any data you want to keep, to a computer or cloud account, before doing the reset.
To "Hard Reset" the phone...
1. Make sure that the phone is actually powered off.
2. Remove your SD card, if there is one in the device.
3. Press...